Andronis L, Oppong RA, Manga N, Senanayake E, Gopal S, Charman S, Giri R, Luckraz H. Is the Venner-PneuX endotracheal tube system a cost-effective option for post cardiac surgery care? Ann Thorac Surg. 2018 Sep;106(3):757-63. doi: 10.1016/j.athoracsur.2018.03.058
Pattanayak SK, Poulos C, Yang JC, Patil SR, Wendland KJ. Of taps and toilets: quasi-experimental protocol for evaluating community-demand-driven projects. J Water Health. 2009 Sep 1;7(3):434-51.