User-agent: Googlebot
Disallow: /impressum.html
Disallow: /impressum.php
Disallow: /images/
Disallow: /css/

User-agent: Googlebot-Image
Disallow: /impressum.html
Disallow: /impressum.php
Disallow: /images/
Disallow: /css/

User-agent: *
Disallow: /impressum.html
Disallow: /impressum.php
Disallow: /images/
Disallow: /css/