Feshchfnko, S.K. <br/><br/>
Asymptotic methods in the theory of liner differential equations   
by S.F.Feshchfnko, N.I.Shkil and L.D.Nikolenko 
 - New York  American Elsevier Publishing Company  1967 
 - xvi, 270p. 
 - Modern Analytic & Computational Methods in Sci. & Mathematic .
<br/><br/><label>LCCN: </label>67-28448 
<br/><br/><label>Dewey Class. No.: </label>515.35  / N676