Intent Specifications and again. Useful ideas: part-whole, information-hiding, and means-end abstraction/refinement hierarchies, notation.
Leading Indicators and Assumption-Based Planning. Useful language: load-bearing, vulnerabile assumptions, buttressing an assumption, signposts, hedging actions, and shaping actions.
Software Requirements & Specifications & Problem Frames. These works extend Polya’s agenda to the domains of software & control systems. Useful language: designations vs. definitions, machine-environment-problem, enzymes.
Systems Performance. Lots of good ideas on how to make things go fast.
Experimental and Quasi-Experimental Designs for Generalized Causal Inference. Recommended by Max Shron in his book: Thinking with Data.
The Complete Book of Scriptwriting. Recommended by colleagues in response to a question on how to learn to tell stories. Useful ideas: “character + desire = goal; goal + conflict = story”.