This is the 'Classic' in the field, as I believe it was the first book that talked about the 'human' side of software/programming. Although the references are quite dated in every way we do software engineering today in specific, the general principles remain.

Incidentally, Weinberg is a prolific author. https://goo.gl/Erp84w I especially like his General Systems Thinking.

Interesting that he was a systems theory guy. My dad was a civil/mechanical engineer and was way into systems theory in the 60s and 70s. The idea, from what I've gathered, is to apply an engineer's toolkit to natural / social science problems. I've got a couple of his old (way out of print) books on systems theory and they're fascinatingly relevant to software development -- particularly for big complex distributed systems. They had to deal with poorly specified problems, emergent behavior, "fuzzy" logic, failure, etc. All problems you face in a real complex software system. These ideas don't get enough press.

This is an excellent book.