This manual is the definitive reference for GNU Bash, the standard GNU command-line interpreter. It covers the current major release of Bash (v3.2, revised printing November 2006).
GNU Scientific Library Reference Manual – Revised Second Edition (v1.8)
This reference manual is the definitive guide to the GNU Scientific Library (GSL), a numerical library for C and C++ programmers. The manual documents over 1,000 mathematical routines needed for solving problems in science and engineering.
Simon&Garfunkel -Feelin’ Groovy – Monterey Pop 1967