Amplitude of the plasma melatonin nycthemeral rhythms is not associated with the dates of onset and offset of the seasonal ovulatory activity in the Ile-de-France ewe Luis Ángel Zarazaga, Benoît Malpaux and Philippe ChemineauReprod. Nutr. Dev., 43 2 (2003) 167-177DOI: https://doi.org/10.1051/rnd:2003015