blakeembrey/pluralize

This is the default automatic pluralization/singularization library used by OurBigBook cross reference title inflection.

That library handles most cases well, but note that English language perfection is never possible with it as it would likely require having word databases which the authors do not wish to support, e.g. to deal with uncountable nouns such as "mathematics" correctly: github.com/plurals/pluralize/issues/60#issuecomment-310740594