1. The Rudin-Keisler ordering of P-Points;Blass;Transactions of the American Mathematical Society,1973
2. Ultrafilter mappings and their Dedekind cuts;Blass;Transactions of the American Mathematical Society,1974
3. Tukey types of ultrafilters;Dobrinen;Illinois Journal of Mathematics,2012
4. Ramsey-Classification Theorems and their application in the Tukey theory of ultrafilters, Part 1;Dobrinen;Transactions of the American Mathematical Society,2013
5. Ramsey-Classification Theorems and their application in the Tukey theory of ultrafilters, Part 2;Dobrinen;Transactions of the American Mathematical Society,2013