GoBase.org – Go Problems (e’ necessaria l’iscrizione al sito)
tasuki/tsumego books · GitHub – collezioni di Cho Chikun, Lee Chang-ho e altre
Classical go problems – On this page you can find lots of classical go problems in SGF format (per utilizzare questi problemi scarica Uligo qui o in Download).
The Quest for Shodan: Problems – blog
Go Problems su OGS.
GoTools – TsumeGo Solving Software
Go Problems on the Internet su Sensei’s Library.
Tsumego, a Go problems mailing list (e’ necessaria l’iscrizione al sito)