1. Johansen, R. H. and J. T. Schulz. 1968. Norchip and Norchief, two new N.D.S.U. potato varieties. North Dakota Farm Research. Vol. 25 No. 6,7–10. July–August, 1968.
2. Johansen, R. H., and Cooperators. North Central Regional potato trials, 1965–1967.