First note that the quantifier c-commands BOOK. Short C-command of this sort is called government. Government differs from c-command in that a node can be governed by only one governor, where as a ...
In the English as in most but not all languages (i.e. Chinese) number can be extracted from the noun leaving a lexical-propositional form of the noun. From book and books we get object predicate: 1.
There is a myriad of ways we can express quantities in English, but there are just a couple words that are much in dispute. Wait. Should that be "there are myriad ways" and "just a couple of words"?