@article{TUW-223002, author = {Huang, Haosheng and Gartner, Georg and Turdean, Timea}, title = {Social Media Data as a Source for Studying People's Perception and Knowledge of Environments}, journal = {Mitteilungen der {\"O}sterreichischen Geographischen Gesellschaft}, year = {2013}, volume = {155}, pages = {291--302} }