Anderson, R., Cerf, V., Harslem, E., Heafner, J., Madden, J., Metcalfe, R., Shoshani, A., White, J., and D. Wood, "Data Reconfiguration Service: An implementation specification", RFC 166, DOI 10.17487/RFC0166, May 1971, <https://www.rfc-editor.org/info/rfc166>.