Siamba D N, Okitoi L O, Watai M K, Wachira A M, Lukibisi F B and Mukisira E A 2007: Efficacy of Tephrosia vogelli
and Vernonia amygdalina as anthelmintics against Ascaridia galli in indigenous chicken. Livestock Research for Rural Development. Volume 19, Article #176. Retrieved
, from http://www.lrrd.org/lrrd19/12/siam19176.htm