Manivanh N, Preston T R, An L V and Thu Hong T T 2018: Improving nutritive value of cassava root (Manihot esculenta Crantz) by fermentation with yeast (Saccharomyces cerevisiae), urea and di-ammonium phosphate. Livestock Research for Rural Development. Volume 30, Article #94. Retrieved , from http://www.lrrd.org/lrrd30/5/noup30094.html