I was wondering if anyone has studied with this book. It's from the 1970s or 80s, and it was used at Yale University's Japanese language program. The author was a professor there. This was the first book that I used to learn Japanese. The amount of repeative drills were helpful for me, but I haven't used the book in 10+ years. I am thinking of picking up the old book and giving it another try, after finishing RTK later this week.