• Giambalvo, Ornella and Roberto Sichera. 2018. “A Proposal to Estimate the Roaming–Dog Total in an Urban Area Through a PPSWOR Spatial Sampling with Sample Size Greater Than Two.” dSeas Working Papers - ISSN 2611-0172 2 (1): 14-14.

  • Sichera, Roberto, and Pietro Pizzuto. 2019. “ConvergenceClubs: A Package for Performing the Phillips and Sul’s Club Convergence Clustering Procedure.” The R Journal 11 (2): 142-51.