@unpublished{TUW-280994, author = {Retscher, G{\"u}nther}, title = {Wi-Fi Positioning in Challenging Urban, Transitional and Indoor Environments}, year = {2019}, note = {invited; talk: Guest Lecture at the GIS Cell of Motilal Nehru Institute of Technology (MNNIT), Allahabad, India; 2019-07-09} }