3DE M W E.Genetical and morphological studies on fringed and on parrot tulips[J].Gartenbauwiss,1939,13:212.
4TIMMER M J G.Growth and selection in tulip planting stock.Ⅱ.The planting stock[J].Bloembollencultuur,1974,84(44):1063-1064.
5TIMMER M J G.Growth and selection in tulip planting stock.Ⅲ.Bulbet production[J].Bloembollencultuur,1974,84(45):1084-1085.
6TIMMER M J G.Growth and selection in tulip planting stock.Ⅳ.Weight of the harvested crop and size distribution[J].Bloembollencultuur,1974,84 (46):1106-1107.
7TIMMER M J G.Growth and selection in tulip planting stock.Ⅴ.Size distribution[J].Bloembollencultuur,1974,84 (47):1127.
8TIMMER M J G.Growth and selection in tulip planting stock.Ⅵ.Selection(planting stock)[J].Bloembollencultuur,1974,84 (48):1155.
9TIMMER M J G.Growth and selection in tulip planting stock.Ⅶ.Selection (markable stock)[J].Bloembollencultuur,1974,84 (49):1178.