References
- Leffingwell , H. A. , Larson , D. A. and Valencia , M. J. 1970 . A study of the fossil pollen Wodehouseia spinata. I. Ultrastructure and comparisons to selected modern taxa. II. Optical microscope recognition of foot layers in differentially stained fossil pollen and their significance . Bull. Can. Petrol. Geol , 18 ( 2 ) : 238 – 262 .
- Nilsson , S. and Muller , J. 1978 . Recommended palynological terms and definitions . Grana , 17 : 55 – 58 .
- Wiggins , V. D. 1976 . Fossil oculata pollen from Alaska . Geoscience and Man , 15 : 51 – 76 .