@misc{Mayr1997diss, author = {Mayr, Rudolf H.}, year = {1997}, school = {Rijksuniversiteit Leiden}, title = {The seal impressions of {Ur} {III} {Umma}}, type = {phdthesis}, } @misc{OzakiYRBC, author = {Tohru, Ozaki and Sigrist, Marcel and Tang, Sergio}, }