You can pay with your credit card and Paypal using the form here below: write the total amount in the first field and the reason in the second field (like Order n. 6000; or Book-code AV/0500 ).
Click the button:
in the next page click on PAESE and choose the nation.
By picking the nation corrisponding to your credit card you will get the whole page to be translated in your language.
You can see what we mean in the pictures below.
Here we show examples of different countries and their translations:
Here you can see better where to click (it's very easy), just note that You can find UK is "Regno Unito", USA is "Stati Uniti", Deutschland is "Germania" and so on.