S. Pattanayak, R. Dasgupta, P. P. Chakravorty, and S. K. Chakraborty, “Changes in Growth Rate and Activities of α Amylase and Cellulase of P. excavatus, an Epigeic Earthworm in Decomposing Leaf Litter of Five Tree Species”, theijst, vol. 2, no. 11, Oct. 2014.