I'm taking a course that's taught out of Shankar, and I'm going to be tested on Tensor Operators, which is 15.3, p.417-421 in Shankar. I've never actually worked with tensors before (except the Maxwell stress tensor in EM), and I find that section too hard to understand. Does anyone know of a more accessible treatment of tensor operators in another textbook? Particularly one that covers basics about tensors instead of assuming some prior exposure. (Tensor operators are way beyond my go-to book, Griffiths.) Here is an example of a problem I'm supposed to be able to do but I'm absolutely lost: Construct a spherical tensor operator of rank 2 from the components of the Cartesian tensor operator Tjk=xjxk. I would really appreciate any suggestions, or even explanations if you feel generous enough to explain tensor operators.