Büchner flask vs Kitassato flask

Büchner flask

noun
  • A type of glass flask used in a laboratory similar to an Erlenmeyer flask, but with a side spout used for connection to an aspirator. 

Kitassato flask

noun
  • Synonym of Büchner flask 

How often have the words Büchner flask and Kitassato flask occurred in a corpus of books? (source: Google Ngram Viewer )