Name Info Provider Link
subscription/membership/fee required Ingenta plc https://www.ingentaconnect.com/openurl?genre=article&issn=&volume=276&issue=6&spage=e976&aulast=Purcell
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=34183507.ui
subscription/membership/fee required Wolters Kluwer https://doi.org/10.1097/SLA.0000000000005034