causal vs linked

causal

adj
  • of, relating to, or being a cause of something; causing 

noun
  • a word (such as because) that expresses a reason or a cause 

linked

adj
  • connected, either with links, or as if with links 

  • having links (between modules, records etc) 

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