diff --git a/xlsx.js b/xlsx.js
index 30ebfb2..6d2a6f6 100644
--- a/xlsx.js
+++ b/xlsx.js
@@ -424,7 +424,7 @@ SSF.load_table = function(tbl) { for(var i=0; i!=0x0188; ++i) if(tbl[i]) SSF.loa
 make_ssf(SSF);
 var XLSX = {};
 (function(XLSX){
-XLSX.version = '0.5.4';
+XLSX.version = '0.5.5';
 var current_codepage, current_cptable, cptable;
 if(typeof module !== "undefined" && typeof require !== 'undefined') {
 	if(typeof cptable === 'undefined') cptable = require('codepage');
@@ -621,7 +621,7 @@ function prep_blob(blob, pos) {
 
 function parsenoop(blob, length) { blob.l += length; }
 /* [MS-XLSB] 2.1.4 Record */
-var recordhopper = function(data, cb) {
+var recordhopper = function(data, cb, opts) {
 	var tmpbyte, cntbyte, length;
 	prep_blob(data, data.l || 0);
 	while(data.l < data.length) {
@@ -631,7 +631,7 @@ var recordhopper = function(data, cb) {
 		tmpbyte = data.read_shift(1);
 		length = tmpbyte & 0x7F;
 		for(cntbyte = 1; cntbyte <4 && (tmpbyte & 0x80); ++cntbyte) length += ((tmpbyte = data.read_shift(1)) & 0x7F)<<(7*cntbyte);
-		var d = R.f(data, length);
+		var d = R.f(data, length, opts);
 		if(cb(d, R, RT)) return;
 	}
 };
@@ -1235,6 +1235,11 @@ function insertCommentsIntoSheet(sheetName, sheet, comments) {
 	});
 }
 
+/* [MS-XLSB] 2.5.97.4 CellParsedFormula TODO: use similar logic to js-xls */
+var parse_CellParsedFormula = function(data, length) {
+	var cce = data.read_shift(4);
+	return parsenoop(data, length-4);
+};
 var strs = {}; // shared strings
 var _ssfopts = {}; // spreadsheet formatting options
 
@@ -1325,6 +1330,7 @@ function parse_ws_xml(data, opts) {
 	return s;
 }
 
+
 /* [MS-XLSB] 2.4.718 BrtRowHdr */
 var parse_BrtRowHdr = function(data, length) {
 	var z = {};
@@ -1345,6 +1351,9 @@ var parse_BrtWsProp = function(data, length) {
 	return z;
 };
 
+/* [MS-XLSB] 2.4.303 BrtCellBlank */
+var parse_BrtCellBlank = parsenoop;
+
 /* [MS-XLSB] 2.4.304 BrtCellBool */
 var parse_BrtCellBool = function(data, length) {
 	var cell = parse_Cell(data);
@@ -1380,7 +1389,7 @@ var parse_BrtCellRk = function(data, length) {
 	return [cell, value, 'n'];
 };
 
-/* [MS-XLSB] 2.4.311 BrtCellRk */
+/* [MS-XLSB] 2.4.314 BrtCellSt */
 var parse_BrtCellSt = function(data, length) {
 	var cell = parse_Cell(data);
 	var value = parse_XLWideString(data);
@@ -1388,40 +1397,58 @@ var parse_BrtCellSt = function(data, length) {
 };
 
 /* [MS-XLSB] 2.4.647 BrtFmlaBool */
-var parse_BrtFmlaBool = function(data, length) {
+var parse_BrtFmlaBool = function(data, length, opts) {
 	var cell = parse_Cell(data);
 	var value = data.read_shift(1);
-	data.l += length-9;
-	return [cell, value, 'b' /*, formula */];
+	var o = [cell, value, 'b'];
+	if(opts.cellFormula) {
+		var formula = parse_CellParsedFormula(data, length-9);
+		o[3] = ""; /* TODO */
+	}
+	else data.l += length-9;
+	return o;
 };
 
 /* [MS-XLSB] 2.4.648 BrtFmlaError */
-var parse_BrtFmlaError = function(data, length) {
+var parse_BrtFmlaError = function(data, length, opts) {
 	var cell = parse_Cell(data);
-	var fBool = data.read_shift(1);
-	data.l += length-9;
-	return [cell, fBool, 'e'];
+	var value = data.read_shift(1);
+	var o = [cell, value, 'e'];
+	if(opts.cellFormula) {
+		var formula = parse_CellParsedFormula(data, length-9);
+		o[3] = ""; /* TODO */
+	}
+	else data.l += length-9;
+	return o;
 };
 
 /* [MS-XLSB] 2.4.649 BrtFmlaNum */
-var parse_BrtFmlaNum = function(data, length) {
+var parse_BrtFmlaNum = function(data, length, opts) {
 	var cell = parse_Cell(data);
 	var value = parse_Xnum(data);
-	data.l += length-16;
-	return [cell, value, 'n' /*, formula */];
+	var o = [cell, value, 'n'];
+	if(opts.cellFormula) {
+		var formula = parse_CellParsedFormula(data, length - 16);
+		o[3] = ""; /* TODO */
+	}
+	else data.l += length-16;
+	return o;
 };
 
 /* [MS-XLSB] 2.4.650 BrtFmlaString */
-var parse_BrtFmlaString = function(data, length) {
+var parse_BrtFmlaString = function(data, length, opts) {
 	var start = data.l;
 	var cell = parse_Cell(data);
 	var value = parse_XLWideString(data);
-	data.l = start + length;
-	return [cell, value, 'str' /*, formula */];
+	var o = [cell, value, 'str'];
+	if(opts.cellFormula) {
+		var formula = parse_CellParsedFormula(data, start + length - data.l);
+		o[3] = ""; /* TODO */
+	}
+	else data.l = start + length;
+	return o;
 };
 
-var parse_BrtCellBlank = parsenoop;
-
 /* [MS-XLSB] 2.1.7.61 Worksheet */
 var parse_ws_bin = function(data, opts) {
 	if(!data) return data;
@@ -1453,7 +1480,7 @@ var parse_ws_bin = function(data, opts) {
 					case 'e': p.raw = val[1]; p.v = BErr[p.raw]; break;
 					case 'str': p.v = utf8read(val[1]); break;
 				}
-				if(val[3] && opts.cellFormula) p.f = val[3];
+				if(opts.cellFormula && val.length > 3) p.f = val[3];
 				if((cf = styles.CellXf[val[0].iStyleRef])) try {
 					p.w = SSF.format(cf.ifmt,p.v,_ssfopts);
 					if(opts.cellNF) p.z = SSF._table[cf.ifmt];
@@ -1463,7 +1490,6 @@ var parse_ws_bin = function(data, opts) {
 
 			case 'BrtCellBlank': break; // (blank cell)
 
-			case 'BrtFmt': break; // TODO
 			case 'BrtArrFmla': break; // TODO
 			case 'BrtShrFmla': break; // TODO
 			case 'BrtBeginSheet': break;
@@ -1490,9 +1516,13 @@ var parse_ws_bin = function(data, opts) {
 			case 'BrtFRTBegin': pass = true; break;
 			case 'BrtFRTEnd': pass = false; break;
 			case 'BrtEndSheet': break; // TODO
+			case 'BrtBeginMergeCells': break; // TODO
+			case 'BrtMergeCell': break; // TODO
+			case 'BrtEndMergeCells': break; // TODO
+			case 'BrtLegacyDrawing': break; // TODO
 			//default: if(!pass) throw new Error("Unexpected record " + R.n);
 		}
-	});
+	}, opts);
 	s["!ref"] = encode_range(ref);
 	return s;
 };
@@ -2593,6 +2623,8 @@ function fixopts(opts) {
 
 		['sheetStubs', false], /* emit empty cells */
 
+		['bookSheets', false], /* only try to get sheet names (no Sheets) */
+
 		['WTF', false] /* WTF mode (do not use) */
 	];
 	defaults.forEach(function(d) { if(typeof opts[d[0]] === 'undefined') opts[d[0]] = d[1]; });
@@ -2611,19 +2643,29 @@ function parseZip(zip, opts) {
 		dir.workbooks.push(binname);
 		xlsb = true;
 	}
-	strs = {};
-	if(dir.sst) strs=parse_sst(getdata(getzipfile(zip, dir.sst.replace(/^\//,''))), dir.sst, opts);
 
-	styles = {};
-	if(dir.style) styles = parse_sty(getdata(getzipfile(zip, dir.style.replace(/^\//,''))),dir.style);
+	if(!opts.bookSheets) {
+		strs = {};
+		if(dir.sst) strs=parse_sst(getdata(getzipfile(zip, dir.sst.replace(/^\//,''))), dir.sst, opts);
+
+		styles = {};
+		if(dir.style) styles = parse_sty(getdata(getzipfile(zip, dir.style.replace(/^\//,''))),dir.style);
+	}
+
+	var wb = parse_wb(getdata(getzipfile(zip, dir.workbooks[0].replace(/^\//,''))), dir.workbooks[0], opts);
 
-	var wb = parse_wb(getdata(getzipfile(zip, dir.workbooks[0].replace(/^\//,''))), dir.workbooks[0]);
 	var props = {}, propdata = "";
 	try {
 		propdata = dir.coreprops.length !== 0 ? getdata(getzipfile(zip, dir.coreprops[0].replace(/^\//,''))) : "";
 	propdata += dir.extprops.length !== 0 ? getdata(getzipfile(zip, dir.extprops[0].replace(/^\//,''))) : "";
 		props = propdata !== "" ? parseProps(propdata) : {};
 	} catch(e) { }
+
+	if(opts.bookSheets) {
+		if(props.Worksheets && props.SheetNames.length > 0) return { SheetNames:props.SheetNames };
+		else if(wb.Sheets) return { SheetNames:wb.Sheets.map(function(x) { return x.name; }) };
+	}
+
 	var deps = {};
 	if(dir.calcchain) deps=parseDeps(getdata(getzipfile(zip, dir.calcchain.replace(/^\//,''))));
 	var sheets = {}, i=0;