Older editions of engineering textbooks are sometimes available for "borrowing" in digital format via the Internet Archive (archive.org). You can search there by the title and author.
It emphasizes understanding the "why" behind the methods, particularly the relationship between deformation and applied loads. Focus on Consistency: statically indeterminate structures chu kia wang pdf
: Covers the Force Method (flexibility method), Displacement Method (stiffness method), and Slope-Deflection Method . Displacement Method (stiffness method)