@article {MR4016726,
	title = {The reverse mathematics of Hindman\&$\#$39;s theorem for sums of exactly two elements},
	journal = {Computability},
	volume = {8},
	number = {3-4},
	year = {2019},
	pages = {253{\textendash}263},
	issn = {2211-3568},
	doi = {10.3233/com-180094},
	url = {https://doi-org.proxy.lib.uwaterloo.ca/10.3233/com-180094},
	author = {Csima, Barbara F. and Dzhafarov, Damir D. and Hirschfeldt, Denis R. and Jockusch, Carl G. Jr. and Solomon, Reed and Westrick, Linda Brown}
}