APA

International Union of Public Transport, IUPT/UITP, . (1991). Green light for towns. Bryssel: International Union of Public Transport.

Chicago

International Union of Public Transport, IUPT/UITP, . 1991. Green light for towns. Bryssel: International Union of Public Transport.

Harvard

International Union of Public Transport, IUPT/UITP, . (1991). Green light for towns. Bryssel: International Union of Public Transport.

MLA

International Union of Public Transport, IUPT/UITP, . Green light for towns. Bryssel: International Union of Public Transport. 1991.