WASET
    Taras Agryzkov and  Almudena Nolasco-Cirugeda and  Jos´e L. Oliver and  Leticia Serrano-Estrada and  Leandro Tortosa and  Jos´e F. Vicent,  Using Data from Foursquare Web Service to Represent the Commercial Activity of a City.   journal   = {International Journal of Humanities and Social Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2015, vol. 97(1). 69 - 76
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/10000159.