Some results on functions holomorphic in the unit disk. Peter Lappan Commentarii mathematici Helvetici
A Criterion for a Meromorphic Function to be Normal Peter Lappan — 1974 Commentarii mathematici Helvetici
Fatou Points of Harmonic Normal Functions and Uniformly Normal Functions. Peter A. Lappan — 1967 Mathematische Zeitschrift
Normal families, orders of zeros, and omitted values. Chen, Huaihui; Lappan, Peter — 1996 Annales Academiae Scientiarum Fennicae. Series A I. Mathematica
On the multiplicative behavior of Bloch functions. Danikas, Nikolaos; Lappan, Peter — 1993 Annales Academiae Scientiarum Fennicae. Series A I. Mathematica