headscarf vs keffiyeh

headscarf

noun
  • A more or less square piece of material worn over the head, typically by women, often to protect the hair, or for religious reasons. 

keffiyeh

noun
  • A headdress traditionally worn by some Arabs, also used as a scarf. 

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