  Recently several papers have been published, where "a new mechanism" of dark
matter burning and freezing is suggested. The usual two-body annihilation
process is generalized to multi-body initial states, mostly three-body. These
processes have quite a few interesting cosmological implications. I want to
indicate here that such a process was studied in 1980 to determine the
cosmological number density of the so called theta-particles. The file of the
translated into English original paper and the reference to the published
English version are attached.
