As of 2025, "Basic Circuit Theory" by Desoer and Kuh remains under copyright (McGraw-Hill). You will find numerous sites (Library Genesis, PDF Drive, Academia.edu) hosting scanned copies. However, note the following:
Basic Circut Theory By Charles A. Desoer & Ernest S. Kuh 1969 Hc basic circuit theory charles a desoer ernest s kuh pdf
Desoer and Kuh emphasize two primary systematic methods for formulating network equations, moving away from the ad-hoc inspection methods used in earlier texts. As of 2025, "Basic Circuit Theory" by Desoer
: It is intended for upper-division students and assumes a background in differential equations, matrices, and determinants. As of 2025