References
Edward L. Keenan
(1988)., Natural language motivations for extending categorial grammar, in R. T. Oehrle, E. Bach & D. Wheeler (eds.), Categorial grammars and natural language structures, Dordrecht, Springer, pp. 265-295.
(1979). The correspondence of two corners. Studies in East European Thought 19 (4), pp. 275-283.