A word for blowing air onto baby's tummy to make him (her) laugh

What do you call the action when you press your mouth against baby's tummy and blow air to make the baby laugh?

That is typically referred to as blowing raspberries:

Blowing a raspberry, strawberry or making a Bronx cheer is to make a noise signifying derision, real or feigned. It is made by placing the tongue between the lips and blowing to produce a sound similar to flatulence. In the terminology of phonetics, this sound can be described as an unvoiced linguolabial trill. It is never used in human language phonemically (e.g., to be used as a building block of words), but the sound is widely used across human cultures.

Here is a Google search as they relate to baby tummies.

Zerbert is what I have always heard it called. Several sites of mixed authority confirm.

http://en.wiktionary.org/wiki/zerbert

http://www.urbandictionary.com/define.php?term=zerbert