Electron orbital filling order In the p sub shell there are 3 orbitals, 
m=-1, m=0, m=1 
which are listed by axis x,y, and z. 
Some show as -1=x,0=y,1=z
Another shows -1=x,0=z,1=y
Some pictures and text also show the filling order as ‘xyz’ and others state that the z axis is filled first m=0 and then the x axis as m=-1 making the filling order z,x,y

What is the correct filling order?
If I know this then I can figure out the d and f sub shells.
d~m=-2,-1,0,1,2
F-m=-3,-2,-1,0,1,2,3
Thanks, HJS
There is no order for filling atomic orbitals of the same azimuthal quantum number (l) such as px, py, and pz since they are degenerate ie. have the same energy (however they lose their degeneracy in a magnetic field, see Zeeman effect). Therefore, one electron in a p sub-cell can be in either 3 of them and the order of filling doenst matter. For when more electrons are added in degenerate orbitals look up Hund's rule and the Pauli principle.