The phrase "ready upon request" is grammatically correct and can be used in written English.
Example: The documents will be ready upon request.
Carnivores assigned by the university to fill Synergy vacancies were to exercise extreme consideration to conceal their offensive mastication and be ready to relocate upon request.
TEDx curators will want to get a sense of your stage presence, so give some thought to your sample and have it ready to go upon request.
DNP uses full HD LCD screens made by JVC for it, but the company is ready to install monitors made by other makers upon request.
As for references, just put down "supplied upon request", and then have at least three ready when they are requested.
Waldy's winning qualities are its ready-to-franchise trimmings: wine sold simply as "good" or "better," free anchovies upon request, and rosemary, thyme, oregano and basil that you can snip right off the plant at the condiment bar.
Painkillers are available upon request".
Price upon request at sjphillips.com.
Pricing is all upon request.
I sang songs upon request.
Flights arranged upon request.
