[PyMOL] Selecting single type amino acids within X angstrom from each other

[DimitryASuplatov]

Hello,
I what to select all histidines that lie within 6 angstroms from each
other. If I use 
> select x, resname his within 6 of resname his 
it selects all possible his, obviously. I tried to create a new state
and select his of different states but got the same result for the same
reason.
Do you have any suggestions? Thanks a lot!
SDA