%0 Journal Article
%A D'Alessandro, Flavio
%A Varricchio, Stefano
%T Well quasi-orders, unavoidable sets, and derivation systems
%J RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
%D 2006
%P 407-426
%V 40
%N 3
%I EDP-Sciences
%U http://www.numdam.org/articles/10.1051/ita:2006019/
%R 10.1051/ita:2006019
%G en
%F ITA_2006__40_3_407_0