1. Moriond Workshop on New and exotic phenomena,1990
2. Search for the neutral Higgs boson from Z0 decay
3. G. Altarelli, R. Kleiss and C. Verzegnassi, eds.,Z physics at LEP 1, CERN Yellow Book 89-08.
4. See, for a detailed discussion on this subject, J. Dress and D. Treille, Proc. Intern. Workshop on Radiative corrections for e+e− collisions (Ringberg, Munich), ed. J.H. Kühn (Springer, Berlin) pp. 311, 323.