APA (7th ed.) Citation

Öpik, A. (1934). Ristnacrinus, a new Ordovician crinoid from Estonia. K. Mattieseni trükikoda o./ü.

Chicago Style (17th ed.) Citation

Öpik, A. Ristnacrinus, a New Ordovician Crinoid from Estonia. Tartu: K. Mattieseni trükikoda o./ü, 1934.

MLA (8th ed.) Citation

Öpik, A. Ristnacrinus, a New Ordovician Crinoid from Estonia. K. Mattieseni trükikoda o./ü, 1934.