Warrag, E.I. 1989. Direct and indirect tissue culture micropropagation and greenhouse plantlet evaluation of superior Eucalyptus grandis. Ph.D. dissertation, University of Florida. Gainesville, Florida, USA. pp 141.
Warrag, E.I. 1984. Effect of nitrogen fertilizer and irrigation on Acacia senegal seedling biomass and photosynthesis. M.Sc. thesis, Oregon State University. Corvallis, Oregon, USA.