Name Info Provider Link
free resource Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S0041-008X(19)30438-7
Pneumonia free resource MedlinePlus Health Information https://medlineplus.gov/pneumonia.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=31734322.ui