britannica had to find a way to stay relevant. >> reporter: enter the answer girls, an elite core of research and answer any question a britannica owner might have. >> you would write your question on a postcard, attach one of these stamps, and in return one of the women from the research center would type up and research up to a 10 4,000 word report as an answer to your question. >> reporter: in fact, katharine hepburn's character in desk set. >> the old farmer's almanac. >> reporter: is said to be modelled on the answer girl's director. >> this is from the bible. >> reporter: then there's the whole set club. people who have read an entire edition of the books, including george bernard shaw, tesla founde elon musk. >> it is lengthy. mt. everest of knowledge. >> reporter: and writer a.j. jacobs. how long does that take? >> that took about a year and a half. and reading six hours a day every day. >> reporter: the hardest part, he says, was actually trying to keep all those facts and figures to himself. >> i had all this knowledge. i kind of wanted to share it. and my wife started to f