At 13:18 when Dreyfuss says "War, what is it good for? Absolutely everything." he is paraphrasing the song "War" by Edwin Starr. The original lyrics are "War, what is it good for? Absolutely nothing."
At 42:35 when Henry says "What fools these mortals be" he is quoting Puck from "A Midsummer Night's Dream" by William Shakespeare.