?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Van+Ryn%2C+J.&rft.aulast=Van+Ryn&rft.aufirst=J.&rft.date=1954&rft.btitle=Principes+de+droit+commercial&rft.genre=book