https://avesis.hacettepe.edu.tr/yayin/e3cb0927-9973-4091-a355-41b5b2edae2a/when-some-complement-of-an-exact-submodule-is-a-direct-summand
When some complement of an exact submodule is a direct summand | AVESİS
of andirect summandcomplementexactsubmodule