1. Correns: Über Levkojenbastarde. Botan. Centralbl.84, 97 (1900).
2. Emerson: The genetic relations of plant color in maize. Cornell Univ., Agric. Exp. St. Mem.2, 39 (1921).
3. Kappert: Die Genetik der immerspaltenden Levkojen. Ztschr. indukt Abst.- u. Verebungslehre78, 233 (1937).
4. Saunders: Further studies in Matthiola incana I. sapcolour and surface charakter. Journ. of Gen.14, 101 (1924).
5. Saunders: Matthiola. Bibliographia Genetica4, 141 (1928).