Mechanisms of Circadian Systems in Animals and Their Clinical RelevanceIntroduction to Circadian Rhythms, Clocks, and Its Genes, de la Iglesia Horacio O, Lee Michael L, Aguilar-Roblero Raúl, Díaz-Muñoz Mauricio, and Fanjul-Moles Mária Luisa, p.1 - 12, Cham, Springer International Publishing (2014)