@article{gd09,
    author = {Glander, Tassilo and Döllner, Jürgen},
    journal = {Computers, Environment and Urban Systems},
    title = {Abstract representations for interactive visualization of virtual 3D city models},
    year = {2009},
    number = {5},
    pages = {375--387},
    volume = {33},
    doi = {10.1016/j.compenvurbsys.2009.07.003},
    publisher = {Elsevier},
}