stubborn vs unreliable

stubborn

adj
  • Refusing to move or to change one's opinion; obstinate; firmly resisting; persistent in doing something. 

  • Of materials: physically stiff and inflexible; not easily melted or worked. 

noun
  • Stubbornness. 

  • A disease of citrus trees characterized by stunted growth and misshapen fruit, caused by Spiroplasma citri. 

unreliable

adj
  • Not reliable. 

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