The book excerpt comes from the National Investigations Committee on Aerial Phenomena’s 1964 book, The UFO Evidence.
Quote from the book excerpt:
“Date & Location: Nov 6, 1957; nr. Danville, Ill.
Names: State Policeman Calvin Showers, John Matulis
Description: Brilliant white light, changing to amber and orange, viewed 20 minutes; cruiser radio failed.”
Satellite photo of Danville, Illinois (tageo.com)