1. L. I. Ronkin, Introduction to the Theory of Entire Functions of Several Variables [in Russian], Nauka, Moscow (1971).
2. O. Sire, Rend. Circolo Mat. Palermo,31, 1?91 (1911).
3. P. Lelong, Ann. Scient. École Norm. Supér.,58, 83?176 (1941).
4. M. Sh. Stavskii, Teoriya Funktsii, Funktsional'. Analiz i Ego Prilozhen.,8, 136?142 (1969).
5. L. I. Ronkin, Matem. Sb.,39, 253?266 (1956).