Hey, was it a question or a statement?
As I know, an ideal voltage source is a voltage source that supplies a constant voltage to a circuit despite the current which the circuit draws.
This means that despite the resistance which a load may be in a circuit, the source will still provide constant and steady voltage.
An ideal voltage source has the following characteristic that allows it to act as a 100% efficient source of voltage: it has zero internal resistance.
How about getting a bit more info on the question. I suppose you write a work on it or smth. So I searched for some papers on engineering but included your request too.
So, check them out.
Engineering Instrumentation (a Ph.D. work, btw)
Electronic Principles (Masters)
Good luck with this, undoubtedly, disputable topic!
If that is a topic for an essay and you look for some help, you can always order a custom written paper. Here is a link to the order form, put in the details and wait for a paper to be written. Authors can prove the statement for you, or argue with it, depends on your request. All the best!