WILLIAMS, Donald M. Bird population trends in a patch of temperate forest on the Drakensberg escarpment, Mpumalanga. Biodiversity Observations, [S.l.], p. 1 - 4, feb. 2016. ISSN 2219-0341. Available at: <https://journals.uct.ac.za/index.php/BO/article/view/298>. Date accessed: 17 july 2019.