APA
Langen Eugen,, . (1973). Transnational commercial law. Leiden: A W Sijthoff International Publishing Co.
Chicago
Langen Eugen,, . 1973. Transnational commercial law. Leiden: A W Sijthoff International Publishing Co.
Harvard
Langen Eugen,, . (1973). Transnational commercial law. Leiden: A W Sijthoff International Publishing Co.
MLA
Langen Eugen,, . Transnational commercial law. Leiden: A W Sijthoff International Publishing Co. 1973.