C. I. L. Justino and  L. I. B. Silva and  K. Duarte and  A. C. Freitas and  T. A. P. Rocha-Santos and  A. C. Duarte,  Determination of Volatile Organic Compounds in Human Breath by Optical Fiber Sensing.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology. August 2012, vol. 68(8). 541 - 544[viewed 24 August 2019]. Available from: http://waset.org/publications/5306.