Roy Lewallen , W7EL wrote:
"Do you have a reference which defines field strength in terms of
voltage induced in a wire?"

Here is a reference from a professional source. B. Whitfield Griffith,
Jr. was Director of Advanced Development at General Dynamics Corporation
at Garland, Texas when his book, "Radio-Electronicc Transmission
Fundamentals" was published by Mc Graw-Hill in 1972. On page 322,
Griffith writes:
"The strength of an electromagnetic wave is generally measured in terms
of the intensity of the electric field; this is expressed in volts per
meter, or millivolts or microvolts per meter, as the conditions may
indicate. This value may be understood as being the numbeer of volts
which would be induced in a piece of wire one meter long placed in the
field parallel to the electric lines of force; the induction of voltage
would result from the movement of the magnetic flux across the wire.

Griffith agrees with Terman.

Best regards, Richard Harrison, KB5WZI