From @pamoroso:

I came across two 1990s books with good coverage of NoteCards, i.e. publications that contain substantial material on NoteCards beyond a few mentions and bibliographic references.

The first is the August 1993 edition of Hypertext: Theory into Practice edited by Ray McAleese. Chapter 2 "Navigation and browsing in hypertext" also discusses browsing in NoteCards and includes screenshots. Chapter 3 reprinted the paper "Collaborative writing in NoteCards" by Randall Trigg and Lucy Suchman.

The other book is Hypertext: State of the Art edited by Ray McAleese and Catherine Green (1990). Chapter 19 "CASE: a casa analysis support environment" describes a hypertext system based on NoteCards.