References
- [Fer] Jim Ferry. Solution to The Riddler puzzle on counting the number of possible crossword puzzles. https://github.com/jimferry/crosswords-538. (Accessed on 06/10/2021).
- [Fer14] Kevin K Ferland. “Record crossword puzzles”. In: The American Mathematical Monthly 121.6 (2014), pp. 534–536.
- [Fer20] Kevin K Ferland. “Counting Clues in Crosswords”. In: Recreational Mathematics Magazine 7.13 (2020), pp. 1–7.
- [IS] The Online Encyclopedia of Integer Sequences. A130883. https://oeis.org/A130883. (Accessed on 09/03/2021).
- [McS16] John K. McSweeney. “Analysis of Crossword Puzzle Difficulty Using a Random Graph Process”. In: The Mathematics of Various Entertaining Subjects. Ed. by Jennifer Beineke and Jason Rosenhouse. Princeton: Princeton University Press, 2016. Chap. 8, pp. 105–126.
- [Roea] Oliver Roeder. How Many Crossword Puzzles Can You Make? https://fivethirtyeight.com/features/how-many-crossword-puzzles-can-you-make/. (Accessed on 06/10/2021).
- [Roeb] Oliver Roeder. Time For Some Abstract Math. Drink Up. https://fivethirtyeight.com/features/time-for-some-abstract-math-drink-up/. (Accessed on 06/10/2021).
- [Sho] Will Shortz. Basic Rules. https://cruciverb.com/index.php?action=ezportal; sa=page;p=21. (Accessed on 03/15/2021).