Intelligent Surfaces for 6G Wireless Networks: A Survey of Optimization and Performance Analysis Techniques. - Rawan Alghamdi; Reem Alhadrami; Dalia Alhothali; Heba Almorad; Alice Faisal; Sara Helal; Rahaf Shalabi; Rawan Asfour; Noofa Hammad; Asmaa Shams; Nasir Saeed; Hayssam Dahrouj; et al. (IEEE Access, 2020)