1. Waksman , S.A. 1932.Principles of Soil Microbiology, 14–14. Baltimore: The Williams & Wilkins Co.
2. Mishustin , E.N. 1975.Association of Soil Microorganisms, 69–69. Moscow: Publisher Nauka.
3. Sato , K. and Ushigoshi , A. 1975.Experimental methods of soil bacteria in “Dojobiseibutu Jikkenho (Experimental Methods of Soil Microbiology),”, 43–43. Tokyo: Society of Soil Microbiology, Yokendo Co. (in Japanese)