1. M. Abe and J. O. Smith III. 2004. Design criteria for simple sinusoidal parameter estimation based on quadratic i5nterpolation of FFT magnitude peaks. In Audio Engineering Society Convention 117. Audio Engineering Society.
2. Skype and/or Microsoft. 2017. Skype | Free calls to friends and family. (2017). https://www.skype.com/
3. C. Bettini, X. S. Wang, and S. Jajodia. 2005. Protecting Privacy Against Locationbased Personal Identification. In Proceedings of the Second VDLB International Conference on Secure Data Management. Springer, Berlin, Heidelberg, 185--199.
4. D. Bykhovsky and A. Cohen. 2013. Electrical network frequency (ENF) maximumlikelihood estimation via a multitone harmonic model. IEEE Transactions on Information Forensics and Security 8, 5 (2013), 744--753.
5. J. Chai, F. Liu, Z. Yuan, R. W. Conners, and Y. Liu. 2013. Source of ENF in BatteryPowered Digital Recordings. In Audio Engineering Society Convention 135. AES, Convention, 1--7. http://www.aes.org/e-lib/browse.cfm?elib=17055