Kramer, Horst. “Boundaries of Smooth Strictly Convex Plane Sets”.
Anal. Numér. Théor. Approx.
8, no. 1 (February 1, 1979): 59–66. Accessed April 11, 2025.
https://ictp.acad.ro/jnaat/journal/article/view/1979-vol8-no1-art7
.