Service in the Public Switched Telephone Network/Intelligent Network (PSTN/IN) Requesting InTernet Service (SPIRITS) Protocol Requirements. - Igor Faynberg; Jorge Gato; Hui-Lan Lu; Lev Slutsman (RFC, 2002)

The SPIRITS (Services in PSTN requesting Internet Services) Protocol. - Vijay K. Gurbani; Alec Brusilovsky; Igor Faynberg; Jorge Gato; Hui-Lan Lu; Musa R. Unmehopa (RFC, 2004)