As a first year graduate student, this was the required text in my very first course in seismology! Boy was I intimidated! I had only taken calculus up through ODE's so much of the material in this book was difficult for me to comprehend. I had no clue what a Green's function was. However, I had a good professor and TA and took extensive notes to get by. Fortunately we only used chapters 2,3,4 and 5. Do yourself a favor if you have to use this book, and you're not a calc/physics guru, by obtaining the Stein/Wysession book. It is a lot more user friendly and application oriented. I used that book in a course the next semester on earthquake seismology and a lightbulb came on! I now understood better what Aki and Richards were talking about! I could go back to it as a reference to gain a deeper understanding. As they say, 'Quantitative Seismology' is the "bible" of the subject and so should be in your library. However, it is more of a reference for experienced users.