To the first version from 1989:

German Medical Association (1989): Guidelines for gene therapy in humans. Online Version (German)

To the first version from 1995: 

German Medical Association (1995): Guidelines for gene transfer into human somatic cells. Online Version (German)

The guidelines have now been officially repealed. See also:

German Medical Association (2010): Announcements: Repeal of the guidelines on gene transfer into human somatic cells and dissolution of the Somatic Gene Therapy Commission. Online Version (German)