Jeffry L. Hirst. Connected components of graphs and reverse mathematics. Arch. Math. Log., 31(3):183-192, 1992. [doi]
@article{Hirst92, title = {Connected components of graphs and reverse mathematics}, author = {Jeffry L. Hirst}, year = {1992}, doi = {10.1007/BF01269946}, url = {http://dx.doi.org/10.1007/BF01269946}, researchr = {https://researchr.org/publication/Hirst92}, cites = {0}, citedby = {0}, journal = {Arch. Math. Log.}, volume = {31}, number = {3}, pages = {183-192}, }