Found in 2 comments on Hacker News
wuschel · 2015-04-07 · Original thread
I prefer the Handbook of Mathematics by Bronstein, which is a math reference bible for most science students in Germany.

http://www.amazon.com/Handbook-Mathematics-I-N-Bronshtein/dp...
claudius · 2013-09-09 · Original thread
Bronstein/Semendjajew’s Handbook of Mathematics[0] is something close to what you envision. It’s helpful if you just need to look up a given formulae and understand the larger picture, but it will be incomprehensible if you don’t know at least some maths. Note that the HHGTG, while giving you some information about planets, will be useless unless you know something about hitchhiking, too: Like the Bronstein, it gives you bits and pieces to remember parts of the larger picture, but it doesn’t give the larger picture to you.

[0] http://www.amazon.com/Handbook-Mathematics-I-N-Bronshtein/dp... (apparently without an English Wikipedia article)

Fresh book recommendations delivered straight to your inbox every Thursday.