Shumail and Syed Inzimam Ul Haq, Shah Khalid, Amreen, Somaeeya Bibi,. " 17. Allelopathic effect of Morus alba, Populus nigra and Euphorbia helioscopia on Brassica campestris" Pure and Applied Biology (PAB) [Online], Volume 10 Number 2 (7 November 2020)