Name Info Provider Link
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=37459006.ui
free resource Singapore Medical Association https://doi.org/10.4103/singaporemedj.SMJ-2022-125
free resource Wolters Kluwer https://doi.org/10.4103/singaporemedj.SMJ-2022-125