blini vs potato pancake

blini

noun
  • A small pancake, of Russian origin, made from buckwheat flour; traditionally served with melted butter, sour cream and caviar or smoked salmon. 

potato pancake

noun
  • A shallow-fried pancake of grated potato and egg, often flavored with grated onion 

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