Uslovnyĭ znak--Permʹ
By: Semen Vaksman.
Publisher: Permskoe knizhnoe izd-vo
Published: 1991
Place of publication: Permʹ
Language: rus
Number of pages: 170
Subjects: Geology, Stratigraphic -- Permian.
Notes: Includes bibliographical references (p. 169-[171]).