1981 Some Constituents of Walnut Xylem Exudates and Their Possible Role in Graft Failure Prataviera, Antonio, Kay Ryugo. 1981.
1982 Pistillate Flower Drop; Its Probable Bases with Respect to Shading and Poor Nutrition and a Tentative Recommendation for Future Plantings Ryugo, Kay, David E. Ramos, R.M. Carlson, G.A. Lombardi, A. Prataviera, William Olson, Steven Sibbett. 1982.