Determination of the ψ(3770), ψ(4040), ψ(4160) and ψ(4415) resonance parameters

R values measured with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV are fitted to determine resonance parameters (mass, total width, electron width) of the high mass charmonium states, ψ(3770), ψ(4040), ψ(4160) and ψ(4415). Various effects, including the interferences and relative phases between the resonances, the energy-dependence of the full widths, and the initial state radiative correction, are examined. The results are compared to previous studies.