# The Semrush bot seemed to use loads of bandwidth in March 2018. It is something to do with AdSense and SEO, so disable it!
User-agent: SemrushBot
Disallow: /
User-agent: SemrushBot-SA
Disallow: /

# Other marketing bots
User-agent: AhrefsBot 
Disallow: /
User-agent: MJ12bot
Disallow: /

User-agent: *
Disallow: /audiotracks/
Disallow: /literary/naturebooks/