Name Info Provider Link
free resource Medknow Publications and Media Pvt Ltd https://journals.lww.com/eusjournal/10.4103/eus.eus_51_20
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=32913150.ui
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/32913150/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/32913150