International Colloquium on Group Theoretical Methods in Physics Varna, Bulgaria, Hennig, J., & Doebner, H. D. (1988). Group Theoritical Methods in Physics: Proceedings of the XVI International Colloquium held at Varna, Bulgaria, June 15-20,1987. Springer-Verlag.
Παραπομπή σε μορφή Chicago (17η εκδ.)International Colloquium on Group Theoretical Methods in Physics Varna, Bulgaria, Jorg-D Hennig, και H. D. Doebner. Group Theoritical Methods in Physics: Proceedings of the XVI International Colloquium Held at Varna, Bulgaria, June 15-20,1987. Berlin ; New York: Springer-Verlag, 1988.
Παραπομπή σε μορφή MLA (9th εκδ.)International Colloquium on Group Theoretical Methods in Physics Varna, Bulgaria, et al. Group Theoritical Methods in Physics: Proceedings of the XVI International Colloquium Held at Varna, Bulgaria, June 15-20,1987. Springer-Verlag, 1988.