Manzano, R. M., Carvalho, C. R. F. de, Saraiva-Romanholo, B. M. and Vieira, J. E. (2008) “Chest physiotherapy during immediate postoperative period among patients undergoing upper abdominal surgery: randomized clinical trial”, São Paulo Medical Journal, 126(5), pp. 269–273. Available at: https://periodicosapm.emnuvens.com.br/spmj/article/view/2000 (Accessed: 10 March 2025).