On the disc theorem
Ahlfors' disc theorem for Riemann covering surfaces is extended to normally exhaustible Klein coverings.
Erratum to the paper "On the disc theorem" (Ann. Polon. Math. 55 (1991), 1-10)
Due to a technical error, part of a sentence was omitted on the top of page 8. The first line should read: “where , or , means the number of folds of the covering ending at p, i.e. covering a neighbourhood of p in without covering p itself”.
On the geometric definition of the quasi-conformality
Page 1