Among others, a significant contribution of Buerger et al. is to show that isodesmic reactions can be found automatically using a computer algorithm, rather than having to be conceived of by hand. Their key insight is that finding isodesmic reaction can be viewed as a constrained optimization problem over the stoichiometric coefficients, ν i , for the reference species in the reaction. The constraints can ensure that the requirements of the reaction classes are satisfied, while minimizing the objective function determines which of the reference species should be included in the reaction. Given the size of the reference set, there are many different combinations of reference species that could be included while still satisfying the reaction class constraints. Buerger et al. chose an optimization scheme that aims to find an isodesmic reaction with the fewest reference species and constraining features. This approach can enhance accuracy because using fewer reference species facilitates greater error cancellation by making each reference species more closely resemble the chemical environment and characteristics of the target species. This approach also reduces the propagation of uncertainties from each reference species into the heat of formation of the target species through Equation ( ). Furthermore, Equation ( ) shows the mixed-integer linear programming problem (MILP) defined by Buerger et al. to automatically find isodesmic reactions.