Celebratio Mathematica

R. As­key: “Pos­it­ive Jac­obi poly­no­mi­al sums, III,” pp. 305–​312 in Lin­ear op­er­at­ors and ap­prox­im­a­tion, II (Ober­wolfach, Ger­many, 30 March–6 April 1974). Edi­ted by P. L. Butzer and B. Szöke­falvi-Nagy. In­ter­na­tion­al Series on Nu­mer­ic­al Math­em­at­ics. Birkhäuser (Basel), 1974. Part I was pub­lished in To­hoku Math. J. 24:2 (1972). Part II was pub­lished in Am. J. Math 98:3 (1976). MR 430359 Zbl 0299.​42001 incollection