#

#1 NR #1: #1 E #1:

&lang#langle; &rang#rangle;

S T S_n,k T_n {}_n=1^&infin#infty; {}_n=1^&infin#infty;

&phis#phi;^s_n,k

Babus̆ka and Aziz [72] Bakhvalov [77] Carasso and Stone [75] Ciarlet [78] Ciarlet and Raviart [72] Dunford and Schwartz [63] Dunn [67] Emelyanov and Ilin [67] Fried [73] Gehatia and Wiff [70] Gel'fand and Vilenkin [64] Hadamard [52] Hämmerlin and Hoffman [83] Kuo [75] Lattes and Lions [69] Morozov [85] Oden and Reddy [76] Pinkus [85] Poggio, Torre, and Koch [85] Pour-El and Richards [83] Rokhlin [86] Shilov and Fan Dyk Tin [67] Skorohod [74] Tikhonov [63] Tikhonov and Arsenin [77] GOTA Twomey [77] Wasilkowski [86] Wasilkowski and Woźniakowski [84] Werschulz [82] Werschulz [85] Werschulz [86a] Werschulz [86b] Werschulz [87a] Werschulz [87b] Werschulz [87c] Zenišek [72]