I would like to paraphrase the headline of Peter Greenberg's Jan. 21 article from "High Praise for a Pilot Who Knew, etc." to "High Praise for a Writer Who Knows." In my years of travel and travel reading, I have never read a person who is more knowledgeable than Peter Greenberg. My file cabinets are full of his articles, and it's evident that he does much research on whatever he writes about. His articles touch on subjects no one else writes about, and are of great use to a traveler.