TY  - JOUR 
T1  - Nutrient balance of layers fed diets with different calcium levels and the inclusion of phytase and/or sodium butyrate
JO  - Brazilian Journal of Poultry Science
A1  - Vieira, MM
A1  - Kessler, AM
A1  - Ribeiro, AML
A1  - Silva, ICM
A1  - Kunrath, MA
SN  - 1516-635X
UL  - 10.1590/S1516-635X2011000200011
VL  - 13 
Y1  - 2011
PB  - Brasil 
ER  -