@misc{Stephany,
  author    = {Ursula Stephany},
  title     = {The development of modality in language acquisition},
  issn      = {1615-1496},
  series    = {Arbeitspapier / Institut f{\"u}r Sprachwissenschaft, Universit{\"a}t K{\"o}ln},
  number    = {A.F. 43},
  pages     = {66},
}