A sequence is a unit of conversation that consists of two or more adjacent and functionally related turns .
McLaughlin, Margaret L. 1984.Conversation: How talk is organized. Sage Series in Interpersonal Communication 3. Beverly Hills: Sage. 9683101704.
Hopper, Robert, Susan Koch, and Jennifer Mandelbaum. 1986. "Conversation analysis methods." In Ellis and Donohue 1986