Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/00006396-199408000-00011
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=7816490.ui
	free resource	NCI CPTC Antibody Characterization Program	https://antibodies.cancer.gov/detail/CPTC-PGR-2
	subscription/membership/fee required	Wolters Kluwer	https://doi.org/10.1016/0304-3959(94)90203-8