Linking to non HTML Resources (PDF) (Word doc) etc.

I’m looking for guidance on linking to non-HTML resources in web pages, for
example, pdfs, Word docs, Excel docs. Specifically, is it better to link to
the format name (Word) or (Word doc) or (doc) or (docx) ?
It seems the link text for (pdf) is straightforward as it describes
the_format_AND the file_extension_. However, other common links (Word,
Excel, PowerPoint) the format (Word for example) is different from the file
extension ( doc or docx for example).

Feedback and thoughts are appreciated.

For example:
County Resource (pdf)
County Resource (doc)