Ovsiannikov, L. V. <br/><br/>
Group analysis of differential equations / 
L.V. Ovsiannikov ; translation edited by W. F. Ames 
 - New York :  Academic Press,  1982 
 - xvi, 416 p. ;  24 cm. 
<br/><br/>Includes bibliographical references and index 
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<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations<br/>Transformation groups