Modern Nimzo-Indian

Igor Lysyj is a strong grandmaster with a peak rating of 2700. He is also a FIDE Senior Trainer. Lysyj was Russian champion in 2014, European blitz champion in 2019, won the World Student’s championship in 2008 with the Russian team. Together with 43 other Russian chess players (including Chess Stars authors Khalifman, Kryakvin, Barski), Lysyj signed an open letter to Russian president Vladimir Putin, protesting against the 2022 Russian invasion of Ukraine and expressing solidarity with the Ukrainian people.

Ever since Nimzowitsch introduced his flexible, dynamic defence to the queen's pawn, debate has raged over White's best reply. Many variations

The Nimzo-Indian: 4 e3

Nimzo-Indian Defense - Chess Pathways

The New Old Indian: A Repertoire for Black against 1d4 – Everyman

Nimzo-Indian Chess Books Shop for Nimzo-Indian Chess Books

Unveiling the Secrets of the Nimzo Indian Defense - Remote Chess

The f3 Nimzo-Indian: Part 4 Chess Openings Explained - NM Caleb

A Complete Opening Repertoire for Black after 1.d4 Nf6 2.c4 e6

Queen's Indian Defense - Wikipedia

Chess Opening Basics: The Bogo-Indian Defense - Chessable Blog

Nimzo & Queen´s Indian

Nimzo-Indian Patterns – IM Bryan Smith - Online Chess Courses