@unpublished{TUW-269719, author = {Retscher, G{\"u}nther}, title = {Cooperative Positioning of User Groups in Multi-modal Transit Situations Based on Differential Wi-Fi and Inertial Navigation}, year = {2018}, note = {invited; talk: 5th International Conference Ubiquitous Positioning Indoor Navigation and Location Based Service UPINLBS, Wuhan, China; 2018-03-22 -- 2018-03-23} }