APA
European Tyre and Rim Technical Organisation, . (1991). ETRTO Recommendations 1991. Bryssel: European Tyre and Rim Technical Organisation.
Chicago
European Tyre and Rim Technical Organisation, . 1991. ETRTO Recommendations 1991. Bryssel: European Tyre and Rim Technical Organisation.
Harvard
European Tyre and Rim Technical Organisation, . (1991). ETRTO Recommendations 1991. Bryssel: European Tyre and Rim Technical Organisation.
MLA
European Tyre and Rim Technical Organisation, . ETRTO Recommendations 1991. Bryssel: European Tyre and Rim Technical Organisation. 1991.