1. Keldysh,L.V.: Proceedings of the Ninth International Conference on Semiconductor Physics, Moscow, 1969, p. 1384.
2. Keldysh,L.V.: Eksitony v poluprovodnikakh (Excitons in semiconductors). Nauka 5 (1971).
3. Bagaev,V.S., Galkina,T.I, Gogolin,O.V., Keldysh,L.V.: ZhETF, Pis. Red. 10, 309 (1969); JETP Letters 10, 195 (1969).
4. Bagaev,V.S., Galkina,T.L, Gogolin,O.V.: Kratkie soobshch. po fizike. FIAN N 2, 42 (1970).
5. Bagaev,V.S., Galkina,T.I., Gogolin,O.V.: In: Eksitony v poluprovodnikakh (Excitons in semiconductors). Nauka 19 (1971).