John, A. H. (2020). Behavior Of Individual Orangutan Sumatera (Pongo Abelii) Before Direintroduction At The Orangutan Quarantine Station, Sibolangit, Deli Serdang, North Sumatera. International Journal of Ecophysiology, 2(02), 101-111. https://doi.org/10.32734/ijoep.v2i02.4677