@unpublished{TUW-182932, author = {B{\"o}hm, Sigrid and B{\"o}hm, Johannes and Schuh, Harald}, title = {Zonal tidal variations in UT1 observed by VLBI}, year = {2009}, note = {poster presentation: AGU (American Geophysical Union), San Francisco, USA; 2009-12-13 -- 2009-12-17} }