Since you’re looking for this PDF:
Given the value of this book, here are legitimate channels (avoid piracy): Introduction To Modern Network Synthesis Van Valkenburg.pdf
M.E. Van Valkenburg's "Introduction to Modern Network Synthesis" (1960) is a foundational text focusing on the mathematical principles for designing passive RLC networks, including Positive Real functions, Foster/Cauer forms, and Darlington’s method. While celebrated for its pedagogical clarity in teaching classical synthesis and filter design, the text is best suited as a theoretical resource for passive circuits rather than practical, modern active filter design. Since you’re looking for this PDF: Given the