W. Ait Ahmed and  M. Aggour and  M. Naciri ,  Biogas Control: Methane Production Monitoring Using Arduino.   journal   = {International Journal of Biotechnology and Bioengineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2017, vol. 122(2). 130 - 133
    [viewed 08 May 2024]. Available from: https://publications.waset.org/pdf/10006317.