https://scholar.google.com/scholar_lookup?title=Etiology+of+Dental+Erosion+?+Intrinsic+Factors&author=Scheutzel,+P.&publication_year=1996&journal=Eur.+J.+Oral+Sci.&volume=104&pages=178–190&doi=10.1111/j.1600-0722.1996.tb00066.x