Brigham, Reed O <br/><br/>
Assimilation of organic nitrogen by zea mays and the influence of bacillus subtilis on such assimilation 

 - Michigan : 
 -  car ;   17 x 25 cm. 
<br/><br/> A dissert. subm. in part. fulf. of the req. for. the deg. of Dr. of Phil. in the Univ. of Michigan. Repr. from soil sc. Rutgers College