1. AES, recommended practice for forensic purposes—Managing recorded audio materials intended for examination, AES27-1996.
2. C. Grigoras, The Electrical Network Frequency analysis over audio recordings, Advanced Topics in Electrical Engineering, ATEE 2002.
3. UCPTE, Summary of the current operating principles of the UCPTE, Text approved by the Steering Committee on 28 October, 1998.
4. UCPTE, Ground rules concerning primary and secondary control frequency and active power within the UCPTE, Text approved by the Assembly on 16 April, 1998.