1. C. Autant-Bernard, N. Massard, Scentific interactions, geographic spilovers and innovation, An empirical study on the French case, Second submit to Papers in Regional Science
2. Manuel de prétopologie et ses applications;Belmandt,1993
3. G. Birkhoff, Lattice Theory, AMS Colloq Publications, Providence, RI, 1940 (3rd edition, 1967)
4. A pretopology-based algorithm for structuring data in spaces endowed with weak structure;Bonnevay,1998
5. S. Bonnevay, M. Lamure, C. Largeron, N. Nicoloyannis, A pretopological approach for structuring data in non-metric spaces, Electronic Notes in Discrete Mathematics, vol. 2 (1999). Available from http://www.elsevier.nl/gej-ng/31/29/24/32/23/show/Products/notes/index htt#002 (visited 06/28/2001)