Konstantinov, Ventseslav

[1].

"Opijanenieto ot 'noviia zhivot'" in V omaiata na preobrazhenieto [Plovdiv, 1987], No. 1, pp. 5-(9) [A foreword in this volume]

[2].

"Predislovie " [Opiti vŭrkhu tainata na dukha (Experiments in the Secrets of the Heart)] in Evropeĭskata misŭl [Varna, 1985], No. 1, pp. 5-(10). A foreword in this volume