Link do wspomnianego artykułu: http://polimaty.pl/2015/02/pechowe-liczby/

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Bibliografia:
- Cohen Jennie, Friday the 13th: History of a Phobia,
- LiveScience,13 Freaky Facts About Friday the 13th,
- Friday the 13th: 13 intriguing facts about the infamous day, The Daily Mirror,
- Kosacki Michał, Piątek trzynastego, „Matematyka w szkole”, 2007.
- Roach John, Friday the 13th Phobia Rooted in Ancient History, National Geographic,
- Roach John, Friday the 13th: Why We Fear It; Why It Can't Strike Again in 2012, National Geographic,
- Snopes.com, Friday the 13th,
- Weisstein, Eric W. "Triskaidekaphobia." From MathWorld--A Wolfram Web Resource.