Premise: Alexander Grinberg (Александр Данилович Гринберг, Aleksandr Danilovich Grinberg) (1885–1979) was a Russian and Soviet photographer. n 1908 he was awarded the silver medal in the all-Russian photo exhibition in Moscow and the gold medal in the international photo-exhibition in Dresden.
Hypothesis: Grinberg won a photo-exhibition when he was about 23.