1. The 2020 IHRSA Global Report
https://www.ihrsa.org/publications/the-2020-ihrsa-global-report/
2. European Health and Fitness Market: Report 2019,2020
3. Barómetro do Fitness em Portugal 2019;Pedragosa,2020
4. Barómetro do Fitness em Portugal 2020;Pedragosa,2021
5. An overview of fitness in Portugal: Business models, attraction and building members’ loyalty;Pedragosa,2021