544,905 CONCEPTS Concepts and theories in carcihogenesis : fourth annual ECP / European Organization for Cooperation in Cancer Prevention Studies/ Symposium, Brugge-Belgium, June 11-13, 1986 : abstracts of free communications and summaries of invited lectures / ECP. co-sponsored by the World Health Organization. — /Limercik : Elsevier Scientific Publ. Irleand Ltd. 1986/. — [4], 108 s. : il. ; 24 cm (Cancer Letters, ISSN 0304-3835 ; vol. 30, suppl.)