1. Boardman, N. K.: Comparative photosynthesis of sun and shade plants. - Annu. Rev. Plant Physiol.28: 355–377, 1977.
2. Frank, R.: Grain yield and ear development of spring barley as influenced by environmental conditions during early stages of plant development. - Biol. Plant.22: 274–281, 1980.
3. Gubar’, G. D.: [Photosynthesis and light regime as factors of the mineral nutrition effectivity]. In Russ. - Izv. Akad. Nauk latv. SSR1971 (9): 6–18, 1971.
4. Gubar’, G. D.: [Physiological and biochemical systems of plants during an illumination change from a higher to a lower one]. In Russ. - In:Gubar, G. D., Romanovskaya, O. I., Kreïts-berg, O. E., Peterson, E. K. (ed.): Adaptatsiya Fiziologo-biokhimicheskikh Sistem Rasteniya k Peremene Osveshcheniya. Pp. 88–97. Zinatne, Riga 1977.
5. Gitbar’, G. D., Romanovskaya, O. I., Kreïtsberg, O. E., Peterson, E. K. (ed.): Adaptatsiya Fiziologo-biokhimicheskikh Sistem Rasteniya k Peremene Osveshcheniya. [Adaptation of Physiological and Biochemical Systems of Plants to the Change in Illuminance.] - Zinatne, Riga 1977.