Ritti, Grewe & Kessener 2007, p. 161 Ritti, Tullia; Grewe, Klaus; Kessener, Paul (2007), "A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications", Journal of Roman Archaeology, vol. 20, pp. 138–163, doi:10.1017/S1047759400005341
Ritti, Grewe & Kessener 2007, pp. 149–153 Ritti, Tullia; Grewe, Klaus; Kessener, Paul (2007), "A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications", Journal of Roman Archaeology, vol. 20, pp. 138–163, doi:10.1017/S1047759400005341