1. On L1 Approximation;Pinkus,1989
2. Uniqueness in vector-valued approximation;Pinkus;J. Approx. Theory,1993
3. On best simultaneous approximation in normed linear spaces;Goel;Canad. Math. Bull.,1974
4. Characterization of an element of best ℓp-simultaneous approximation;Goel,1974
5. Applications of Functional Analysis to Approximation Theory;Deutsch;Lecture Notes,1992