I recommend that you should complete a general introductory course beforehand. Paul Hartley, German Business Situations. You will need an advance level of German to benefit from it. The BBC education website has a language element with on-line learning units that link to BBC programmes and courses. There are resource lists, learning tips and a directory that links to other language sites.
Every subject has a subject number.
Subject numbers run from 001 to 999. . This is written on the spine usually. Materials are shelved in subject number order from 001 - 999.