Are you aware of a public API that returns the VIAF author list given an ISBN? OCLC had the Classify API until recently, but it has been discontinued.
https://www.oclc.org/go/en/classify-discontinuation.html

@despens @edsu In 1998, I had a Perl script with WWW::Mechanize that did that for me: it browsed Google and provided me with the first results.