summary vs tip of the iceberg

summary

adj
  • Performed speedily and without formal ceremony. 

  • Concise, brief or presented in a condensed form 

  • Performed by skipping the procedures of a standard and fair trial. 

noun
  • An abstract or a condensed presentation of the substance of a body of material. 

tip of the iceberg

noun
  • A small indication of a larger possibility; the first part encountered of a problem that is much bigger than it seems. 

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