1. Burkhardt, H.: 1969, Dispersion Relation Dynamics, American Elsevier, New York, pp. 80–92.
2. Merzbacher, E.: 1970, Quantum Mechanics, 2nd edn, Wiley, New York, pp. 215–250.
3. Newton, R. G.: 1966, Scattering Theory of Waves and Particles, McGraw-Hill, New York, pp. 3–150.
4. Perkins, D. H.: 1972, Introduction to High Energy Physics, Addison-Wesley, Reading, Mass., pp. 265–287.
5. Rapp, D.: 1971, Quantum Mechanics, Holt, Rinehart and Winston, New York, pp. 519–551.