A. K. DAS, R. P. PURKAYASTHA AND. “INTER-SPECIFIC STERILITY IN COPRlNUS-A FACTOR IN BIOCONTROL OF WEED FUNGI IN MUSHROOM BED”. Indian Phytopathology, vol. 43, no. 3, Jan. 2002, pp. 427-30, http://epubs.icar.org.in/index.php/IPPJ/article/view/22613.