Ashford, J. R., Brown, S., Duffield, D. P., Smith, C. S., & Fay, J. W. J. (1961). The Relation between Smoking Habits and Physique, Respiratory Symptoms, Ventilatory Function, and Radiological Pneumoconiosis amongst Coal Workers at Three Scottish Collieries.

Ashford, J. R., Susannah Brown, D. P. Duffield, C. S. Smith, and J. W. J. Fay. The Relation between Smoking Habits and Physique, Respiratory Symptoms, Ventilatory Function, and Radiological Pneumoconiosis Amongst Coal Workers At Three Scottish Collieries. 1961.

Ashford, J. R., et al. The Relation between Smoking Habits and Physique, Respiratory Symptoms, Ventilatory Function, and Radiological Pneumoconiosis Amongst Coal Workers At Three Scottish Collieries. 1961.