"Booksellers will wear masks, and customers will be required to wear masks in places where the state mandates it. Trolleys have been set out with signs instructing customers to leave any books they have touched on the cart, so that the books can be placed in quarantine for five days — long enough for any potential viral particles to die off — then reshelved."

Libraries are going to have to consider the same thing, as well as limit users. Not just limit because of distancing, but limiting to avoid a giant pile of books waiting to be decontaminated. You can inadvertently touch a great deal, reaching for books ... and how long could the virus live moist inside tightly closed pages? No studies on that one, I'll bet.