TY  - JOUR 
T1  - A simple model for circadian timing by mammals
JO  - Brazilian Journal of Medical and Biological Research
A1  - Cardoso, F.R.G.
A1  - de O. Cruz, F.A.
A1  - Silva, D.
A1  - Cortez, C.M.
SN  - 0100-879X
UL  - 10.1590/S0100-879X2009000100017
VL  - 42 
Y1  - 2009
PB  - Brasil 
ER  -