Some abnormally coiled ammonites from the Upper Cretaceous of Angola. American Museum novitates ; no. 1222

@inproceedings{Haas1943SomeAC,
  title={Some abnormally coiled ammonites from the Upper Cretaceous of Angola. American Museum novitates ; no. 1222},
  author={Otto Haas and Chester Wesley Washburne},
  year={1943}
}