Silivong P, Preston T R, Van N H and Hai D T 2015: Effect of water spinach and biochar on methane production in an in vitro system with substrate of Bauhinia acuminata or Bitter Neem (Azadirachta indica) leaves. Livestock Research for Rural Development. Volume 27, Article #57. Retrieved , from http://www.lrrd.org/lrrd27/3/sili27057.html