Give a reference to why the sender an element of communication?

One reference that discusses the sender as an element of communication is the book "Communication in Our Lives" by Julia T. Wood. In this book, Wood explains how the sender plays a crucial role in the communication process by encoding and transmitting messages to the receiver. The sender's choice of words, tone, and nonverbal cues can greatly impact the effectiveness of the communication exchange.

Shannon, C. E., & Weaver, W. (1949). The mathematical theory of communication. Urbana: University of Illinois Press.