van Schayck, C. P., Folgering, H., Harbers, H., Maas, K. L., & van Weel, C. (1991). Effects of allergy and age on responses to salbutamol and ipratropium bromide in moderate asthma and chronic bronchitis.

van Schayck, C P., H. Folgering, H. Harbers, K L. Maas, and C. van Weel. Effects of Allergy and Age On Responses to Salbutamol and Ipratropium Bromide in Moderate Asthma and Chronic Bronchitis. 1991.

van Schayck, C P., et al. Effects of Allergy and Age On Responses to Salbutamol and Ipratropium Bromide in Moderate Asthma and Chronic Bronchitis. 1991.