WASET
    Salim Istyaq and  Mohammad Sarosh Umar,  Hybrid Authentication Scheme for Graphical Password Using QR Code and Integrated Sound Signature.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2018, vol. 134(2). 111 - 115
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/10009015.