Encyclopedias

Encyclopedia of Mathematics 
Online Wiki
The original articles are from the online Encyclopaedia of Mathematics, published by Kluwer Academic Publishers in 2002
Published by Springer, in cooperation with the European Mathematical Society

Wolfram MathWorld 
Online encyclopedia of mathematics

Hd.B. 00       Mathematical Software      (Mathematica ; Maple ...)
        See also: 217   Program listings. Documentation. Software manuals (MATLAB)

Hd.B. 01      Encyclopedias (Mathematics)

Hd.B. 05      Mathematicians - Directories

Hd.B. 06      Teaching & research

Hd.B. 08      Dictionaries   Handbooks

Hd.B. 08.1   Dictionaries (Mathematics)

Hd.B. 09      Mathematical writing

Hd.B. 09.1    Mathematical writing - Computerized typesetting
      (see also 237.6   TeX ; LaTeX ; PostScript ...)

Hd.B. 52-109    Handbooks in various subjects

TAB. 01-109     Tables in various subjects