GFCI in an aluminum wired circuit

My house was built in the early seventies and is wired with aluminum.
I am planning to add a couple of receptacles.  One is adjacent to a
bathroom sink and so a GFCI is needed.  In preparation I am reading a
DIY book on Basic Wiring.  One caution that has been repeated is to
Hire an electrician to install any GFCI on a circuit having aluminum
wires, even if they are clad in copper.  From this I infer that there
is a way to add a GFCI to an aluminum wired circuit if one knows how. 
Can anyone tell me the precautions that need to be taken (besides
hiring an electrician?)
I know that certain potential problems exist with aluminum wired
circuits.  Some of these are: expansion/contraction of aluminum over
time can loosen attachment screws in receptacles and switches (leading
to arcing); aluminum exposed to air will oxidize and the oxidation has
high resistance (leading to high temperatures); joining aluminum to
copper wires cannot be done safely). I am wondering what danger adding
a GFCI to a circuit introduces?
Thanks for any info.  I do not want to do anything that will result in
an unsafe situation, but if there is a way to do it if proper care is
taken, then I would like to.