I've made a sort of project of reading or rereading the oldest books I could find about the UFO phenomenon, because they are closest in time to the original incidents. J. Allen Hynek was an important figure in the early days, because he was hired by the US government to more or less debunk UFO sightings as all being astronomical phenomena. He was originally skeptical, but, being a true and honest scientist, when the evidence didn't fit the prevailing opinion, he changed his mind. (Fancy that, somebody changing his mind based on the evidence. Rare now.) This is his account of his experiences and his conclusions about how study of the subject should be approached. I give it five stars for authenticity, and three stars for being readable (he gets a bit excited and loses his objective tone sometimes). Well worth anybody's time, as a bit of history.