Well a compilation is already a creative act on it's own and works as an ensemble.

Especially if the wording it consistent, avoiding repetitions and is clear in terminology. °

As an example:

If I wrote a Perl tutorial, and occasionally copied a line verbatim from the perldocs without referencing individually, this might be OK. ³

But if I literally copied >50% without any reference, this wouldn't really qualify as a tutorial... ²

°) I could tell a story or two about a neighboring university were the math classes for anthropologists are taught by biologists and the students are left to belief it's their fault if the lessons made no sense.

²) if I wrote "you shall not murder", I wouldn't really bother citing the accurate passages from the Quran, Bible, Tanakh or Code of Hammurabi. But if I copied a whole passage verbatim, the source should be stated.

³) Me, I would personally take care to mention somewhere to the end that small passages were taken from perldoc and thank the authors.