according to van der waerden's obituary of emmy noether, she did not follow a lesson plan for her lectures, which frustrated some students. instead, she used her lectures as a spontaneous discussion time with her students, to think through and clarify important problems in mathematics. some of her most important results were developed in these lectures, and the lecture notes of her students formed the basis for several important textbooks, such as those of van der waerden and deuring.