Maximow developed and introduced a unitarian theory of hematopoiesis, a theory upon which the modern concept of blood cells' origin and differentiation is based. He introduced the term "stem cell."  Translated into English by Claudia Koltzenburg, Alexey Chukhlovin, Athanasius Anagnostou, and Carol Stocking as "The Lymphocyte as a stem cell common to different blood elements in embryonic development and during the post-fetal life of mammals," Cell Therapy and Transplantation, 1 (2009) doi:10.3205/ctt-2009-en-000032.01 Available from the Wayback Machine at this link.

Maximow’s blood regeneration theory.