@article{1973-hopcroft-duality
,note={Note: see also older version $0}
,author={John E. Hopcroft and J. Musinski}
,ISSN={0097--5397}
,journal={SIAM Journal on Computing}
,MR={56:17201}
,pages={159--173}
,title={{Duality applied to the complexity of matrix multiplications and other bilinear forms}}
,volume={2}
,year={1973}
}