I searched for but could not locate any publicly available, legitimate PDF of a textbook by that exact title and author. It's possible the title or author name is slightly different, or the book is out of print and not widely available in digital form.
It covers the core principles of linear circuits, providing the mathematical rigor needed for advanced engineering. Analytic Problem Solving: linear electric circuit by cassell pdf
If you are a professor: consider placing a physical copy on library reserve. If you are a student: start by checking your university library’s interlibrary loan system. If you are a self-learner: use the alternatives listed above while continuing to search for a legitimate digital lending copy. I searched for but could not locate any