@ARTICLE{Mueller:2008:MTW,
    author = {T. M{\"u}ller},
    title = {{Exact geometric optics in a Morris-Thorne wormhole spacetime}},
    journal = {Phys. Rev. D},
    year = {2008},
    volume = {77},
    pages = {044043},
    pacs = {04.20.-q, 04.20.Jb},
    doi = {10.1103/PhysRevD.77.044043}
}