Changes in supply and demand for work on the basis of qualification and profession structures in the Opolskie Province in years 1998 and 2004 - Wróblewska, Małgorzata (. The @role of human resources in Śla̜sk Opolski competitiveness. - Opole : Politechnika Opolska, 2006. - 108 S.. - graph. Darst., 2006)