1. 秋元和實・長谷川四郎（1989）日本近海における現生底生有孔虫の深度分布―古水深尺度の確立に向けて―．地質学論集，no. 32, 229-240．
2. 青島睦治（1987）荒川層群の有孔虫化石(1)．栃木県博研報，5, 37-55．
3. Barron, J. A. (1980) Lower Miocene to Quaternary diatom biostratigraphy of Leg 57, off northern Japan, Deep Sea Drilling Project. In Scientific Party, Init. Rep. Deep Sea Drilling Project, 56 & 57, Part 2, Washington (U. S. Govt. Printing Office), 641-685.
4. Blow, W. H. (1969) Late Middle Eocene to Recent planktonic foraminiferal biostratigraphy. In Brönnimann, P. and Renz, H. H. eds., Proc. First International conference on planktonic microfossils (Geneva, 1967), Leiden, no. 1, 199-421.
5. 古沢菜穂子・松居誠一郎・酒井豊三郎（1987）上部中新統田野倉層及び入江野層の貝化石群．栃木県博研報，5, 57-79．