extracting the monomials from a multivariable polynomial



Hello,
 Is there a function which will extract the list of monomials in a 
multivariable polynomial?

For instance, I would like to get the following results for the 
indicated polynomials:

p: 2*x^2*y^2 -> [2*x^2*y^2]

p: 2 + x^2 + y  -->  [2, x^2, y]

p: x*y + 3*x^3 - y^4 --> [x*y, 3*x^3, - y^4]

TIA,
 -sen