Turhan Koyuncu and  Fuat Lule,  Design, Manufacture and Test of a Solar Powered Audible Bird Scarer.   journal   = {International Journal of Agricultural and Biosystems Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2009, vol. 30(6). 345 - 347
    [viewed 26 February 2020]. Available from: https://publications.waset.org/pdf/15034.