Gilbert, Doris Wilcox. <br/><br/>
Study in depth / 
by Doris Wilcox Gilbert. 
 - Englewood Cliffs, N. J. :  Prentice-Hall,  1966. 
 - xvi, 207 p. :  ill. ;  28 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Study, Method of.