Lots of danish, dutch, american and belgian entries there...
I haven't seen any "proper" german beers around. Our hotel had Becks but I'm not keen on that Beer in the UK (and I'm a big German beer fan). I suspect lots of those mentioned might be brewed under licence in Turkey in any case. If anything alcoholic has been imported in to Turkey, it'd be quite expensive anyway.
Tell them just to stick to the Efes - a fine pilsener which somehow tastes even better in Turkey anyway.
Can you still get Pera? I tried it once but just went back to Efes straight after.