Toward Building Conversational Spoken-Language Interfaces: Acknowledgment Use in American English and Mexican Spanish. - Karen Ward; Tasha Hollingsed; Javier A. Aldaz Salmon (ENC, 2003)

Acknowledgment Use with Synthesized and Recorded Prompts. - Karen Ward; Tasha Hollingsed; Javier A. Aldaz Salmon (SIGDIAL Workshop, 2004)