The papers available in PDF are denoted by PDF. The papers available in PostScript are denoted by PS. The papers, which have new versions available in PDF or PostScript are denoted by (PDF) or (PS), respectively. Similarly, the papers with complete text available in HTML are denoted by HTML. The scanned reprints available in PDF 300dpi for printing are denoted by PDF300. The papers available in GIF 150dpi (or 120dpi) for screen preview are denoted by GIF150 (or GIF120).
We are going to further extend the number of papers available electronically.