"We can't only listen once. We've got to listen twice because sometimes when the stories are told, you hear something and you learn something.

VOA: standard.2010.02.19

Then don't forget to include all of the expenditure that only comes once or twice a year - Christmas presents, holidays and the like.

BBC: Fergus Muirhead

But my dirty little secret is that I don't particularly enjoy birding in Central Park and have only done so once or twice.

WSJ: Park Filmmakers Wing It

Gastroenterologists generally only do an endoscopy when the patient doesn't respond to taking a PPI twice a day for 12 weeks.

WSJ: Why Your Heartburn Drugs Don't Work