- "Together with The Times of London, yours [NYT] is...
- 1931: Dell Crossword Puzzle Magazine
- 1938: Scrabble; Bletchley Park
- 1939: Frank Lewis
- "By the late 1930s, the crossword puzzle boom...
- the term "crossword" first appeared in a dictionary
- Dell (Crossword Puzzle) Magazine; longest running crossword magazine
- Criss-Crosswords => Lexiko => "Scrabble"
- Can You Solve a UK Intelligence Agency's Christmas Puzzle? 12/10/2015
- Turing's Spirit Hovers at a Restored Estate Bletchley Park, where the Real 'Imitation Game' Happened; 11/28/2014
- At Bletchley Park, a Reminder About the History of Cracking Codes 8/9/2014
- Happy birthday, Crossword: a very efficient aptitude test 12/6/2013
- Wikipedia: Bletchley Park; cryptanalysis
- Bletchley Park: Home of the CodeBreakers Google Cultural Institute; slideshow
- World War II: 1939-1945; Frank Lewis US Army code breaking; later NSA
- The Women Who Helped America Crack Axis Codes review of Code Girls: The Untold Story of the American Women Code Breakers of World War II; "Did they like doing crossword puzzles?"; 11/6/2017
- NSA Uses Twitter Puzzle To Recruit Computer Hackers 5/16/2014
- Can You Crack the NSA's Top-Secret Crossword Puzzles? the National Security Agency Just Released Archive Editions of its In-House Magazine, Cryptolog; 3/28/2013
- Frank Lewis, US Codecracker, Ingenious Puzzle Designer 12/2/2010
- NSA's Puzzle Periodical: 2017; 2016; 2015; NSA Cryptochallenge: Puzzle of the Week
- CryptoKids: America's Future Codemakers & Codebreakers Codes & Ciphers; Games & Activities
- The Winter Murder Case. A Philo Vance Story Van Dine, S. S.; "A detective story is a grim business, and the reader goes to it, not for literary furbelows and style and beautiful descriptions and the projection of moods, but for mental stimulation and intellectual activity -- just as he goes to a ball game or to a cross-word puzzle? Dissertations on etymology and orthography interspersed in the definitions of a cross-word puzzle would tend only to irritate the solver bent on making the words interlock correctly."
- First Times Crossword UK; 2/1/1930
- Wikipedia: 1930s
- The Decades That Invented the Future: Part 4: 1930s Radar; Works Progress Administration; Schrödinger's Cat; Pop Culture Characters; Nylon; Z1 computer by Zuse; Ballpoint Pen; Kodachrome; Mildred "Babe" Didrikson Zaharias; War of the Worlds; Electric Pinball; Volkswagen Beetle; 11/9/2012
- Paleofuture: 1930s