be obstinate

References in classic literature ?
For Heaven's sake don't be obstinate, for when others are obstinate I am obstinate likewise, and then I become ferocious and headstrong, and there's my friend, who is even more headstrong and ferocious than myself.
But in any case, an expensive and necessary operation cannot suffer because we decided to be obstinate on the field.
I'm sure the boss doesn't intend to be obstinate, but he is right at retirement age .