1. High energy beam optics;Steffen,1965
2. A first- and second-order matrix theory for the design of beam transport systems and charged particle spectrometers;Brown;SLAC no. 75,1967
3. H. Enge and S. Kowalski, private communication.
4. Proc. 4th Intern. Conf. on Magnet technology;Thiessen,1972