Citation: Camara, F.; Oberti, R.; Iezzi, G.; Della Ventura, G. (2003). The P2_1/m - C2/m phase transition in synthetic amphibole Na NaMg Mg5 Si8 O22 (OH)2: thermodynamic and crystal-chemical evaluation Sample: T = 140 C. Physics and Chemistry of Minerals, 30, pp. 570-581.