Zoelzer, F., Engel, C., Paul W., D., & Anna Lena, B. (2020). A comparative study of nightly allonursing behaviour in four zoo-housed groups of giraffes (Giraffa camelopardalis) . Journal of Zoo and Aquarium Research, 8(3), 175-180. https://doi.org/10.19227/jzar.v8i3.508