Muhammad Akram Nasir, Muhammad Afzal, Shakeel Ahmed, Naveed Anwar Virk and Attiq Akhter
Journal of Biological Sciences 1 ( 5 ): 336 - 337 , 2001
Shakeel Ahmed and Muhammad Aslam
Pakistan Journal of Biological Sciences 3 ( 12 ): 2163 - 2164 , 2000