?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=De+Leeuw%2C+TG&rft.aufirst=TG&rft.aulast=De+Leeuw&rft.atitle=Gabapentin+as+add-on+to+morphine+for+severe+neuropathic+or+mixed+pain+in+children+from+age+3+months+to+18+years+-+evaluation+of+the+safety%2C+pharmacokinetics%2C+and+efficacy+of+a+new+gabapentin+liquid+formulation%3A+study+protocol+for+a+randomized+controlled+trial&rft.title=Trials&rft.date=15+January+2019&rft.volume=20&rft.issn=1745-6215&rft.genre=article