Spedding, C. R. W. <br/><br/>
Biological efficiency in agriculture / 
C.R.W. Spedding, J.M. Walsingham and A.M. Hoxey 
 - London :  Academic Press,  1981 
 - 383 p. ;  24 cm. 
<br/><br/><label>ISBN: </label>0126565600 
<br/><br/><label>LCCN: </label>80-042231 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Field crops--Physiology