This list is a little different from the first list. There are 7 series of books by 5 authors. Only one represents a truly "other" universe; the remainders are set in our universe -- either in the distant past or in the distant future.
*Asimov -- Foundation Series (Distant Future)
*Auel -- Earth's Children (Distant Past)
*Donaldson -- Mordant (Other Universe)
*Donaldson -- Gap Series (Distant Future)
*McDevitt -- Alex Benedict Series (Distant Future)
*McDevitt -- Academy Series (Distant Future -- not in the Alex Benedict Universe)
*Smith -- Lensmen Series (Distant Future)
