Reports from more than one account?

[Elmar Schmeisser]

Newbie question - getting disjoint accounts and their children into one
report:  Specifically one specific expense account (under Expenses), and
one specific income account (under income) onto one page.  I thought
that the profit/loss report should do it, but neither it, nor any other
report, seems to allow selecting multiple disjunct (non-adjacent)
accounts.  How can I do this?  - Elmar