...LehrbegrifFe unter den Slaven', Theologischf Studien und Kritiken, Hamburg, 1837, pt 2, pp. 357-66; C. Schmidt, Histoire et doctrine de la secte des Cathares ou Albigeois, vol. i, p. 7; vol. n, pp. 271 et seq.; D. Tsukhlev, Историн не българската пъркна,...