Zend certified PHP/Magento developer

What are the syntax rules for the Google ngrams search engine? [migrated]

I was trying to determine which of the following two phrases occurs most often in Spanish literature. However, I must have misspelled something or used the wrong delimiters to separate the two phrases:

  • pimienta de cayena
  • chile de cayena

However, only results for “pimienta de cayena” are visible.

How do I show “chile de cayena” on the same chart?

screen capture of Google Books Ngram Viewer with pimeinta de cayena,chile de cayena

If I am searching for an entire phrase, instead of one word, do I have to wrap the phrase in quotation marks?

What is the correct syntax?

pimeinta de cayena,chile de cayena