Looking for Expert in Marginal Accounting [Preferably in German language. English is also Welcome]

Hello,

I need some help in Marginal Accounting. I have theoretical questions about:

*Basic concepts of cost and revenue accounting.

*Cost elements

*Cost center

*cost unit accounting

*Income statement

HOW IS THE PAYMENT?
The payment is hourly!

To prove your knowledge I would like to send you a few smaller questions, to see if it fits.