Русский: "Ф. В. Токарев с сыном Николаем у ручного пулемета системы Максима-Токарева образца 1925 г." или еще "Токарев с сыном в первом помещении КБ ТОЗ. 1925 г."
http://www.opoccuu.com/tokarev-s-synom.jpg also appears in the book Болотин, Давид (1995) История советского стрелкового оружия и патронов, Полигон, ISBN5-85503-072-5, on p. 168 (different cropping) the version with the same cropping as here is labeled "Токарев с сыном в первом помещении КБ ТОЗ. 1925 г. (фото из собрания ВИМАИВ и ВС)" in an article from Kalashnikov magazine 2011/6, p. 32
Note that in 1996 (US URAA date) in Russia their 1993 law was in force. This granted copyright 50 years p.m.a. or 50 years from date of creation for anonymous works. Therefore, the photo was public domain in Russia at URAA date, so it is also public domain in the US. (I wish there was a template for this).
Comment
This image is cropped differently than what can bee seen in the book by Bolotin: the gun's muzzle and bipod are visible in the book, although the right shoulder of Tokarev Jr. is left out over there. This image is of higher quality than what I can obtain by scanning the small, half-column photo in that book. Perhaps someone can find a big & uncropped version somewhere.