?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Keogh%2C+RH&rft.aufirst=RH&rft.aulast=Keogh&rft.title=Statistics+in+Medicine&rft.issn=0277-6715&rft.pages=3661-3678&rft.issue=25&rft.date=10+November+2018&rft.atitle=Multiple+imputation+in+Cox+regression+when+there+are+time-varying+effects+of+covariates&rft.volume=37&rft.genre=article