1. Ahrenfeldt, R. H. 1960. Mating behaviour of Euproctus asper in captivity. Brit. J. Herpetol. 2: 194–197.
2. Arnold, S. J. 1972. The evolution of courtship behavior in salamanders. Ph. D. thesis, Univ. of Michigan, Ann Arbor.
3. Arnold, S. J. 1976. Sexual behavior, sexual interference and sexual defense in the salamanders Ambystoma maculatum, Ambystoma tigrinum and Plethodon jordani. Z. Tierpsychol. 42: 247–300.
4. Baker, W. 1848. Description of a species of newt. The Zoologist 6:2198.
5. Ball, R. W., and D. L. Jameson. 1966. Premating isolating mechanisms in sympatric and allopatric Hyla regilla and Hyla californiae. Evolution 20: 533–551.