J. Paul Roth. Minimization over Boolean Trees. IBM Journal of Research and Development, 4(5):543-558, 1960. [doi]
@article{Roth60, title = {Minimization over Boolean Trees}, author = {J. Paul Roth}, year = {1960}, doi = {10.1147/rd.45.0543}, url = {http://dx.doi.org/10.1147/rd.45.0543}, researchr = {https://researchr.org/publication/Roth60}, cites = {0}, citedby = {0}, journal = {IBM Journal of Research and Development}, volume = {4}, number = {5}, pages = {543-558}, }