AKHTENSKITE—THE Natural Analog of ɛ-MnO2 Chukhrov, F. V. ; Gorshkov, A. I. ; Sivtsov, A. V. ; Berezovskaya, V. V. ; Dikov, Yu. P. ; Dubinina, G. A. ; Varinov, N. N. Abstract Publication: International Geology Review Pub Date: October 1989 DOI: 10.1080/00206818909465960 Bibcode: 1989IGRv...31.1068C