The book "Occupational Psychology: Its Problems and Methods" by Harry L. Hollingworth (Harry Levy) and Leta Stetter Hollingworth is a classic study in the field of occupational psychology. In this book, the authors examine the psychological aspects of choosing a profession, identify key problems in this area, and propose methods of research and solving these issues. Based on his own scientific observations and empirical data, the book highlights a variety of factors that influence career choice, career development, and job satisfaction. The authors consider the influence of personal traits, interests, abilities, environment and other factors on professional choice and success at work. "Professional psychology: its problems and methods" became an important contribution to the general theory of professional choice and development of human capabilities. This book will be useful both for students studying psychology and for professionals in the field of career counseling and personnel management.