Name Info Provider Link
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=25993387.ui
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/25993387/
subscription/membership/fee required Wolters Kluwer https://doi.org/10.1213/ANE.0000000000000790