APA

Van Ek J A, Trim J L M, . (1991). Waystage 1990. Strasbourg: Council of Europe.

Chicago

Van Ek J A, Trim J L M, . 1991. Waystage 1990. Strasbourg: Council of Europe.

Harvard

Van Ek J A, Trim J L M, . (1991). Waystage 1990. Strasbourg: Council of Europe.

MLA

Van Ek J A, Trim J L M, . Waystage 1990. Strasbourg: Council of Europe. 1991.