Postgraduate Corner - the one stop resource platform for postgraudates
The following online sources introduce you to various tools (e.g., expertise, control, body language, grit) which you can use to construct a successful viva.
In this book, Judee Burgoon, the doyen of nonverbal communication, presents authoritative information on what you'd like to know about gestures, vocalics, and appearance.
Gallo's book on Steve Jobs' presentation techniques is an excellent resource on constructing the spoken style of your presentation—the style you must use to engage with your audience.
This book provides evidence-based strategies for communicating for successful outcomes.