1. Extreme points and extremum problems in H1;de Leeuw;Pacific J. Math.,1958
2. Past and future;Helson;Math. Scand.,1967
3. Lectures on Hp Spaces;Koosis,1980
4. T. Nakazi, Extremal problems in H1 for noncontinuous kernels, preprint.
5. T. Nazaki, Strong factorizations and extremal problems in H1, preprint.