Waksman, Selman A. <br/><br/>
Microbiological Analysis of Soil as an Index of Soil Fertyliti 

 - New Jersey,   1922. 
 - 2 v. ;   18 cm. 
<br/><br/> Contiene:    Vol.III:Influence of fertilization upon numbers of microorganisms in the soil     Vol.VI: Nitrification