Fridriksone, 1971
From dinoflaj3
Fridriksone, A.I., 1971: Akritarkhi Baltisphaeridium i gistrikhosfery(?) iz kembriiskikh otlozhenii Latvii., Geological Survey Institute, Vilnius, no.3, p.5-22, pl.1-3. (Russian original not available to present authors.)