@article{thiele1985three, title = {Three-Level Tone Test Signal for Setting Audio Levels}, author = {Thiele, Neville}, journal = {J. Audio Eng. Soc}, volume = {33}, number = {12}, pages = {963--967}, year = {1985}, url = {https://www.aes.org/e-lib/browse.cfm?elib=4409} }