?url_ver=Z39.88-2004&rft_id=PQ+ETD%3A593513&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Walker&rft.aufirst=K&rft.au=Walker%2C+K&rft.tpages=190&rft.title=Analysis+of+repeated+measurements+from+medical+research+when+observations+are+missing&rft.date=30+June+2007&rft.degree=Doctoral&rft.inst=UCL+(University+College+London)