IMDB : 39 Steps, The (1935) - Full cast and crew for the film, and other information from the Internet Movie Database.

Greatest Films: The Thirty-Nine Steps - Detailed review, synopsis and discussion of thematic elements in the film

Scotland the Movie Location Guide - The 39 Steps - Scottish filming locations for The 39 Steps

Britmovie - The 39 Steps - Cast information, trailer, and review.