Tsagris, M;    Fragkos, K;      (2016)    Umbrella Reviews, Overviews of Reviews, and Meta-epidemiologic Studies: Similarities and Differences.                    In: Biondi-Zoccai, G, (ed.) Umbrella Reviews: Evidence Synthesis with Overviews of Reviews and Meta-Epidemiologic Studies. (pp. 43-54).   Springer: Cham, Switzerland.