Marealle, Wilfred, Tomas Holmern, و Eivin Røskaft. 2020. "Factors Affecting Group Size and Vigilance Behaviour of Maasai Giraffe (Giraffa Camelopardalis Tippelskirchi) on the Serengeti-Ngorongoro Ecosystem, Tanzani"a. East African Journal of Environment and Natural Resources 2 (1), 14-23. https://doi.org/10.37284/eajenr.2.1.133.