Pervin, S., Hoqlle, M.S., Iahiruddin, M. and Mian, M.H. 1999. ?EFFECTS OF UREA, AZOLLA AND SESBANIA INCORPORATION ON THE CONCENTRA- TION AND UPTAKE OF N, P, K AND S IN RICE (ORYZA SATIVA). Biological Sciences - PJSIR. 42, 3 (Jun. 1999), 145–149.