Cobzaş, Ş. “Antiproximinal Sets in Banach Spaces of Continuous Functions”. Anal. Numér. Théor. Approx. 5, no. 2 (August 1, 1976): 127–143. Accessed August 10, 2022. https://ictp.acad.ro/jnaat/journal/article/view/1976-vol5-no2-art2.