@unpublished{TUW-120872, author = {Mendes Cerveira, Pj. and Tanir, Emine and Wresnik, J{\"o}rg and B{\"o}hm, Johannes and Tesmer, V. and Schuh, Harald}, title = {Datum deficiency in VLBI analysis}, year = {2007}, note = {poster presentation: 18th European VLBI for Geodesy and Astrometry, Wien; 2007-04-12 -- 2007-04-13} }