1. R. H. Knapp, Jr., and D. ter Haar,Bogolyubov Festschrift, 1969, in press.
2. N. N. Bogolyubov and S. V. Tyablikov,Dokl. Akad. Nauk SSSR
126:53 (1959);Sov. Phys.-Dokl.
4:604 (1959).
3. S. V. Tyablikov,Ukrain. Mat. Zhn.
11:287 (1959).
4. V. L. Bonch-Bruevich and S. V. Tyablikov,Green Function Methods in Statistical Mechanics, Moscow, 1961; Amsterdam, 1962.
5. D. N. Zubarev,Usp. Fiz. Nauk
71:71 (1960);Sov. Phys.—Usp.
3:320 (1960).