The Penguin Dictionary of Curious and Interesting Numbers

Wells, D. The Penguin Dictionary of Curious and Interesting Numbers（英语：The Penguin Dictionary of Curious and Interesting Numbers） London: Penguin Group.

有形數 費馬多邊形數定理 The Penguin Dictionary of Curious and Interesting Numbers, David Wells (Penguin Books, 1997) ISBN 0140261494. Polygonal numbers (MathWorld)

Encyclopedia of Integer Sequences. OEIS Foundation. [2016-05-29]. （原始内容存档于2019-04-19）.  David Wells: The Penguin Dictionary of Curious and Interesting Numbers

百萬網：一個英國人籌措大學學費的計劃 Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 185. "1,000,000 = 106"

Periodic Table. [2012-12-08]. （原始内容存档于2016-04-10）.  Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 133