@unpublished{TUW-240181, author = {Kwak, Younghee and B{\"o}hm, Johannes and Hobiger, Thomas and Plank, Lucia}, title = {A combined TRF of GNSS single differences and VLBI at the Observation Level during CONT11}, year = {2015}, note = {talk: IUGG 2015 General Assembly, Prag; 2015-06-22 -- 2015-07-02} }