none 10.1070/RM1965v020n04ABEH001188 Steklov Mathematical Institute Steklov Mathematical Institute 2731 18571895 4167 2008091008073900 10.4213 2024-10-03T13:09:24Z 2005-11-07T10:02:42Z 97 Russian Mathematical Surveys Russ. Math. Surv. 0036-0279 1468-4829 08 31 1965 20 4 ELEMENTARY THEORIES Yu L Ershov I A Lavrov A D Taimanov M A Taitslin 08 31 1965 10 16 2007 35 105 10.1070/RM1965v020n04ABEH001188 2008091008073900 https://www.mathnet.ru/eng/rm6048