Reference

Vladimir Jan Amos Novak (1955): The Question of the Gradient-factor and its Function in Insect Metamorphosis. Observations to H. E. Hinton‘s paper: The initiation, maintenance, and rupture of diapause: A new theory (The Entomologist, 86, 279-291, 1953). – Beiträge zur Entomologie = Contributions to Entomology – 5: 457 - 461.