A cross-sectional survey was conducted in May and June of 2015, after ethical clearance was approved by The Hong Kong Institute of Education.
Se llevó a cabo una encuesta transversal en mayo y junio del 2015 después de su aprobación ética por el Instituto de Hong Kong de Educación.
Estudo transversal realizado no período de maio a junho de 2015 após a aprovação ética pelo The Hong Kong Institute of Education.