Walker, Helen Mary,  1891- <br/><br/>
Elementary statistical methods / 
by Helen M.Walker and Joseph Lev 
 - 3rd ed. 
 - New York :  Holt, Rinehart & Winston,  1969 
 - 432 p. :  ill. ;  23 cm. 
 - International series in decision processes .
<br/><br/> Previous ed. : Holt, 1958 
<br/><br/><label>ISBN: </label>0030811309 
<br/><br/><label>LCCN: </label>72-077816