Fire in microgravity

I have been thinking about the way the fire behaves in microgravity. I
have found little information on this in the internet, so I am mostly
just wondering, and these thoughts are what I want to share with you
for discussion:

In absence of gravity, the flames create a sort of sphere around the
core of the fire (of course, this sphere will be limitated by the
object in fire; depending on its shape, we will have an almost entire
ball for a match, or just a semi-sphere in the case of a fire on a flat
surface). Well, if the core of the fire is surrounded by flames
(incandescent gases), how can the core be feed by fresh oxygen to keep
the fire burning? Maybe this creates a sort of pulsating effect on the
spherical flame, contracting it when the oxygen is running out, and
allowing thus the flux of more oxygen into the core, which feeds again
the flames to its previous size?

If someone knows where can I find more information on this matter, I
would be very grateful. Best regards,

Javier Casado
Space stuff in spanish in: http://es.geocities.com/fjcasadop