1. Pure and Applied Mathematics;C. Bennett,1988
2. Lecture Notes in Pure and Applied Mathematics;P. K. Kamthan,1981
3. S. G. Krein, Yu. I. Petunin, and E. M. Semenov, Interpolation of Linear Operators (Nauka, Moscow, 1978) [in Russian].
4. H. Triebel., Interpolation Theory, Function Spaces, Differential Operators (VEB Deutscher Verlag der Wissenschaften, Berlin, 1978).
5. D. J. H. Garling, “On symmetric sequence spaces,” Proc. London Math. Soc. 16, 85–106 (1966).