Malevanyy G. G., Piryatin V.D. The method of least squares in hydrogeological studies and calculations. In Russian /Malevanyy G.G., Piryatin V.D. Sposob naimenshikh kvadratov v gidrogeologicheskikh issledovaniyakh i raschetakh. Second edition, revised and supplemented by Kharkiv Publishing House of Kharkiv University, 1972, 236 p. Please contact us for details on condition of available copies of the book. SKUalb3b8016febbb52961