Bibliography
- Between Silk and Cyanide by Leo Marks, HarperCollins (1998) ISBN 0-00-255944-7; Marks was the Head of Codes at SOE and this book is an account of his struggle to introduce better encryption for use by field agents; it contains more than 20 previously unpublished code poems by Marks, as well as descriptions of how they were used and by whom.
Read more about this topic: Poem Code