Maria Diogo and  Patrícia Diogo,  The Stone in the Identity of the Landscape.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2012, vol. 71(11). 709 - 714
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/6542.