Voprosy golocena sbornik statej k VI meždunarodnogo kongressu INKVA v Varšave 1961 = Holocene problems : a symposium of papers for the VI-th international INQUA congress Warsaw 1961 = Holoceno klausimai : straipsniu̧ rinkinys - Nejštadt, Mark Il'ič 1903-1985 (1961)