@inproceedings{KP84,
   author = {E. Kranakis and I.C.C. Phillips},
   title = {Partitions and Homogeneous Sets for Admissible Ordinals},
   booktitle = {Models and Sets, Proceedings of the Logic Colloquium
held in Aachen, July 18-23, 1983, Part I},
   editor = {G.H. M\"{u}ller and M.M. Richter},
   series = {Lecture Notes in Mathematics},
   publisher = {Springer-Verlag},
   volume = 1103,
   pages = {235-260}, 
   year = 1984 
}