Best one-sided L1 approximation to the Heaviside and sign functions. - Jorge Bustamante; José M. Quesada; Reinaldo Martínez-Cruz (J. Approx. Theory, 2012)

Quasi orthogonal Jacobi polynomials and best one-sided L1 approximation to step functions. - Jorge Bustamante; Reinaldo Martínez-Cruz; José María Quesada (J. Approx. Theory, 2015)