User-agent: Googlebot
Disallow: /*.pdf$
Disallow: /*.jpg$
Disallow: /*.gif$
Disallow: /*.bmp$
Disallow: /*.txt$

User-agent: Slurp
Disallow: /*.pdf$
Disallow: /*.jpg$
Disallow: /*.gif$
Disallow: /*.bmp$
Disallow: /*.txt$

User-agent: "*"
Disallow: /*.pdf$
Disallow: /*.jpg$
Disallow: /*.gif$
Disallow: /*.bmp$
Disallow: /*.txt$