@article{SchoenbergerPennerWeissenborn1997,
  author    = {Sch{\"o}nberger, Manuela and Penner, Zvi and Weissenborn, J{\"u}rgen},
  title     = {Object placement and early German grammar},
  year      = {1997},
  language  = {en}
}
@article{WeissenbornPennerSchoenberger1994,
  author    = {Weissenborn, J{\"u}rgen and Penner, Zvi and Sch{\"o}nberger, Manuela},
  title     = {The acquisition of object placement in early German and Swiss German},
  year      = {1994},
  language  = {en}
}