Anyone have a recommendation of a good introduction to corpus linguistics for undergraduate students? Ideally, I'd like a single book that covers both the how and the why, but I'd gladly take things that work separately. I've got some good materials on how to do linguistics with R, but worry that they seem a bit opaque or advanced for students without much of a background in math. Ideally, this would be a course that a student in her second year with only general introductions to the field would be able to handle, but if it's something that would work for third-year students, that's okay too. I've seen the titles available, but I'm hoping that people with experience using or teaching the books can point me toward or away from one book or another so that I can order some desk copies.