Keep it Simple with Black: A Solid and Straightforward Chess Opening Repertoire for Black: Christof Sielecki: 9789493257511: Amazon.com: Books
English Opening (1.c4) – IM Christof Sielecki – iChess.net
Christof Sielecki, Chessable Author - Chessable
Banter Blitz with Christof Sielecki | Special Community Battle | Banter Blitz with Christof Sielecki | Special Community Battle . | By chess24 | Facebook
An Interview with IM Christof Sielecki - Chessable Blog