APA (7e ed.) Bronvermelding

(2015). Plunkett Analytics Reports. Fitness Centers, Gyms and Exercise and Fitness Programs Industry (US). Plunkett Research, Ltd..

Chicago (17e ed.) Bronvermelding

Plunkett Analytics Reports. Fitness Centers, Gyms and Exercise and Fitness Programs Industry (US). [S.l.]: Plunkett Research, Ltd., 2015.

MLA (9e ed.) Bronvermelding

Plunkett Analytics Reports. Fitness Centers, Gyms and Exercise and Fitness Programs Industry (US). Plunkett Research, Ltd., 2015.