Omnibus Volumes

Baen Books have published Poul Anderson's main future history series, the History of Technic Civilization, in seven uniform omnibus volumes as The Technic Civilization Saga, compiled by Hank Davis.

Isaac Asimov has a parallel series:

The End Of Eternity, poor though that is as a time travel novel;

those Robot short stories that can be regarded as consistent with his future history;

the four Robot novels;

the three Galactic Empire novels;

the two pre-Foundation novels;

the original Foundation series;

the two later Foundation novels.

There are also additional volumes, e.g., a Robots Trilogy and a Second Foundation Trilogy, by other authors.

Asimov's series is better known but Anderson's is better written.