⁣Solzhenitsyn writes:

…And from the astonishing disclosure in 1990 we learned that the famous “mobile gas chambers” were invented — as it turns out — not by Hitler during World War II, but [rather] the Soviet NKVD in 1937 by Isai Davidovich Berg, the head of the administrative and maintenance section of the NKVD of Moscow Oblast (sure, he was not alone in that enterprise, but he organized the whole business).
https://christiansfortruth.com/mobile-gas-vans-not-invented-by-nazis-but-by-the-communist-jew-isai-berg-to-mass-murder-ukrainians-during-holomodor/