Children's Momentary Behavioural Engagement and Class Size: A National Systematic Observation Study - Jennifer E. Symonds; Ricardo Böheim; Matthew P. Somerville; Edward Baines; Xin Tang; Niamh Oeri; Raven Rinas; Florian Jonas Buehler; Gertraud Benke; Aisling Davies; Seaneen Sloan; Dympna Devine; et al. (Frontline Learning Research, 2025)