TY  - SER
AU  - Bailey, Robert C.
AU  - Olson Jodi
AU  - Pepper, Sarah L.
AU  - Porszasz, Janos 
AU  - Barstow, Thomas J.
AU  - Cooper, Dan M.
TI  - The level and tempo of children´s physical activities: an observational study
PY  - 1995///
CY  - Estados Unidos
PB  - American College of Sport
ER  -