Michele Sinico,  The Effect of Symmetry on the Perception of Happiness and Boredom in Design Products.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2020, vol. 158(2). 93 - 96
    [viewed 20 April 2024]. Available from: https://publications.waset.org/pdf/10011040.