1. www.goldennumber.net/beauty/3.
2. Samuel Obara, The Golden Ratio in Art and Architecture, J.Wilson, University of Georgia, Department of mathematical education.
3. Parmanand Singh, The So-called Fibonacci numbers in Ancient and Medieval India, Historia Mathematica, Vol.12, pp.229–244, 1985.
4. www.amnh.org/learn-teach/young-naturalist-awards/winning-essays2/2011-winning-essays/thesecret-of-the-fibonacci-sequence-in-trees
5. www.redicecreations.com/article.php?id=16548