407 | | Seedless varieties worthy of attention | ANONYMOUS | The growing edge, 60-64 | | ES 3-22-18 | 61 |
692 | | Register of New Fruit and Nut Varieties, List 41 | OKIE, W.R. | HortScience 37 (2) 256-257 | 2002 | TROLLHAUGEN | 257 |
1218 | | A Review of Cold Climate Grape Cultivars | SMILEY, L. | Iowa State University | 2016 | TROLLHAUGEN | 127 |
1222 | | Development of Cold Climate Grapes in the Upper Midwestern U.S.: The Pioneer Work of Elmer Swenson | CLARK, M.D. | Plant Breeding Reviews Vol. 4, Chapt. 2 | 2019 | TROLLHAUGEN | 4 |