citronella vs roosa oil

citronella

noun
  • An essential oil obtained from this plant, often used as an insect repellent. 

  • A tropical Asian grass, Cymbopogon nardus, that has citrus-scented leaves. 

roosa oil

noun
  • grass oil 

How often have the words citronella and roosa oil occurred in a corpus of books? (source: Google Ngram Viewer )