1. A. Zygmund, Trigonometric Series, vol. 1, 2, Cambridge Univ. Press, Cambridge, 1959, 1960.
2. Princeton Mathematical Series;E M Stein,1970
3. S. Yano, “Notes on Fourier analysis. XXIX. An extrapolation theorem”, J. Math. Soc. Japan., 3:2 (1951), 296–305.
4. E. I. Berezhnoi and A. A. Perfil’ev, “A sharp extrapolation theorem for operators”, Funkts. Anal. Prilozhen., 34:3 (2000), 66–68; English transl.: Functional Anal. Appl., 34:3 (2000), 211–213.
5. E. I. Berezhnoi, “A sharp extrapolation theorem for Lorentz spaces”, Sibirsk. Mat. Zh., 54:3 (2013), 520–535; English transl.: Siberian Math. J., 54:3 (2013), 406–418.