There are times when a patrolman must use a reference work, whether it is to find a mathematical constant or for astrogation purposes, or to see what steps to take in a specific emergency. It would be dumb and pointless to try and memorize everything. There is more than one person can know

It is for these reasons that reference books exist. Libraries have a whole section called "Reference" which includes periodicals. Do make use of the reference books here and, in real life, take a trip to your loccal library and look into the reference section; you will probably find something you like there.