Throughout his entire creative life, the outstanding Soviet writer, social thinker, paleontologist, doctor of biological sciences and founder of modern taphonomy Ivan Antonovich Efremov (04/10/1908 - 10/5/1972) maintained an extensive correspondence. This publication contains letters under one cover Soviet and foreign scientists, including A. Bystrov, P. Chudinov, D. Watson, E. Olson and others. The compiler and author of the comments is Ph.D. N.V. Boyko. The text is published on the website noogen.su.