Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/0014-5793(89)80263-7
	free resource	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0014-5793&date=1989&volume=246&issue=1-2&spage=109
	free resource	NCI CPTC Antibody Characterization Program	https://antibodies.cancer.gov/detail/CPTC-PTHrP-1