Existence of Chebyshev Centers, Best n-Nets and Best Compact Approximants
Dan Amir, Jaroslav Mach, Klaus Saatkamp · Transactions of the American Mathematical Society · 1982
Dan Amir, Jaroslav Mach, Klaus Saatkamp, Existence of Chebyshev Centers, Best $n$-Nets and Best Compact Approximants, Transactions of the American Mathematical Society, Vol. 271, No. 2 (Jun., 1982), pp. 513-524