Recorded from March 18th to June 6th, 1973 in Prague (tracks 1-5). LP Supraphon/Artia 1 13 1586 (1974) - export version with other cover under the title of "The Blue Effect: A Benefit Of Radim Hladík" LP Supraphon 1 13 1777 (1975) CD Bonton 495274-2 (2000) with 2 bonus tracks (in track listing), remastered by Jiří Charypar in studio ADK Prague