Meško, Ivan. “Discrete Piecewise Linear \(l_1\) Approximation”.
Anal. Numér. Théor. Approx.
18, no. 2 (August 1, 1989): 139–145. Accessed April 11, 2025.
https://ictp.acad.ro/jnaat/journal/article/view/1989-vol18-no2-art5
.