Uniform Convergence on Compacta and Locally Univalent Analytic Functions of Finite Order. Douglas Campbell — 1973 Monatshefte für Mathematik
An Estimate for Meromorphic Functions with Finite Spherical Surface Area Satisfying a Minimum Modulus Condition. Douglas Michael Campbell — 1975 Monatshefte für Mathematik
Linear spaces and linear-invariant families of locally univalent analytic functions. Joseph A. Cima; Douglas A. Campbell — 1971 Manuscripta mathematica