Psilomelane from Bulgaria
Bulgaria | |
| I. Kostov, V. Breskovska, J. Mincheva-Stefanova, G. Kirov (1964): Minerals of Bulgaria. Sofia, Bulgaria, 540 pp. (in Bulgarian). |
| Kostov et al : Minerals of Bulgaria (1964) |
Bulgaria | |
| I. Kostov, V. Breskovska, J. Mincheva-Stefanova, G. Kirov (1964): Minerals of Bulgaria. Sofia, Bulgaria, 540 pp. (in Bulgarian). |
| Kostov et al : Minerals of Bulgaria (1964) |