Anne Swinscow has written several popular guide books on Dartmoor Letterboxing: Dartmoor Letterboxes ISBN 0-9509114-2-9; More Dartmoor Letterboxes ISBN 0-9509114-1-0 ; 101 Dartmoor Letterboxes: But Not How to Find Them! (with John Howard) ISBN 0-9509114-3-7. Janet Palmer has written a brief guide to Dartmoor Letterboxing: Let's Go Letterboxing: A Beginner's Guide (2nd revised edition) ISBN 1-898964-33-5. Alan Rowland has written a specialised guide to the letterboxes on Lundy published in 2006 ( the 20th Anniversary of) Lundy Letterboxes ISBN 978-0-9506177-8-7 The Letterboxer's Companion by Randy Hall was published in 2003 and focuses on letterboxing in North America; ISBN 0-7627-2794-2.