Authors: O'HERNE L VAN DER VLERK I M

Citation: L. O'Herne et M. Van Der Vlerk I, Geological age determinations on a biometrical basis (conparison of eight parameters), Bollettino della Societa paleontologica italiana , 10(01), 1971, pp. 3-18

Authors: VAN DER VLERK I M DE BOCK J F SIROTTI A

Citation: M. Van Der Vlerk I et al., Biometrical investigations on Operculina and Lepidociclina. A test on their degree of objectivity and reliability for geological age and determinations, Bollettino della Societa paleontologica italiana , 11(01), 1972, pp. 86-99