"I would highly recommend the book "Mastering Chess Endgame Calculation: Theory and Exercises - Level 1 of the Trilogy That Will Take Your Game to the Next Level!" by GM Adrian Mikhalchishin and IM Tadej Sakelsek. This book is the first part of a trilogy and is designed to help chess players up to 1700 rating improve their endgame calculation skills. The book covers all of the important theoretical positions and techniques that are necessary for successful endgame play, and includes 400 carefully selected exercises to help readers practice and reinforce their understanding of these concepts. The exercises are arranged in a progressive manner. What sets this book apart from other endgame books is authors' clear and concise explanations of the key concepts and ideas combined with practical exercises.
Overall, the first book of the trilogy is an excellent resource for any chess player looking to improve their endgame skills. Mihalcisin's and Sakelsek's thorough coverage of important theoretical positions and techniques, combined with their clear explanations and numerous exercises, make this book an ideal choice for players up to 1 700 rating."

GM Georg Mohr