1. A. Martin:Nuovo Cimento,47 A, 265 (1967).
2. A. K. Common:Nuovo Cimento,53 A, 946 (1968).
3. G. Auberson, O. Piguet andG. Wanders:Communication to the XIV International Conference on High-Energy Physics, Vienna, 1968, quoted in the rapporteur’s talk ofA. Wightman (to be published).
4. F. K. Cheung: private communication. I am grateful toDr. Cheung for pointing out a numerical mistake in ref.(1)A. Martin:Nuovo Cimento,47 A, 265 (1967).