This is the only Vietnam guidebook which has language tonal markings on the map street names, landmarks, cities/towns, etc. I am Vietnamese-American, so I speak Vietnamese, but don't necessarily know my way around every nook and cranny of Vietnam, so it is super helpful to be able to PRONOUNCE street names to cab drivers, xe om drivers, etc by reading the map, rather than embarrassing myself as a Viet Kieu by trying to sound out the name without any tonal markings, which happens with other guidebook maps that don't have the tonal markings. There are some spelling mistakes, but it is the best one I've seen out there.