Thus, he may have made significant changes to his original vision, as set forth in the Foundation trilogy.

The Foundation Trilogy won the award, which further added to the popularity of the series.

The three books together came to be called The Foundation Trilogy.

The three books together came to be known as The Foundation Trilogy.

These three books are now known collectively as the Second Foundation Trilogy.

Foundation and Empire was the second book in the Foundation trilogy.

But, um, have you ever read The Foundation Trilogies?

It was published in 1986, four years after the first sequel to the Foundation trilogy, which is titled Foundation's Edge.

In the first decade of the existence of The Foundation Trilogy it may have earned something like $1500 total.

I re-read The Foundation Trilogy and, taking a deep breath, dived into the task.