Timofeev, B.V.,
1963
Fitoplankton ordovika i silura Sibirskoy Platformy.
Akademiya Nauk SSSR (Doklady Earth Science Sections), v.149, no.2, p.399-402. (Published English translation dated 1965 in Doklady Earth Science Sections, American Geological Institute, v.149, p.45-48. Russian original not available to present authors.)