The [*Encyklopädie der mathematischen Wissenschaften mit Einschluss ihrer Anwendungen*](https://archive.org/details/encyklomath101encyrich) (20+ volumes) was organized from basic to advanced, as was its [French translation](http://gallica.bnf.fr/Search?q=Encyclopédie+des+sciences+mathématiques+pures+et+appliquées). It's a bit dated though.

Nowadays there is also the Russian *Encyclopaedia of Mathematical Sciences* translated by Springer (80+ volumes).