Harvey Friedman, Jeffry L. Hirst. Weak Comparability of Well Orderings and Reverse Mathematics. Annals of Pure and Applied Logic, 47(1):11-29, 1990.
@article{FriedmanH90,
title = {Weak Comparability of Well Orderings and Reverse Mathematics},
author = {Harvey Friedman and Jeffry L. Hirst},
year = {1990},
researchr = {https://researchr.org/publication/FriedmanH90},
cites = {0},
citedby = {0},
journal = {Annals of Pure and Applied Logic},
volume = {47},
number = {1},
pages = {11-29},
}