1. Observation of nonclassical effects in the interference of two photons
2. Measurement of subpicosecond time intervals between two photons by interference
3. Violation of Bell's Inequality and Classical Probability in a Two-Photon Correlation Experiment
4. Dicke, R.H. 1964.Proceedings of the Third International Conference on Quantum Electronics, Edited by: Grivet, P. and Bloembergen, N. 35–35. New York: Columbia U.P.
5. Richter, G. 1977.75 Jahre Quantentheorie, Edited by: Brauer, W., Streitwolf, H.W. and Werner, K. 245–245. Berlin: Akademia. 1988,Ann. Phys., Leipzig,45,564.