Besides the title reference to Enter the Dragon (1973), there is another reference. As Cole is training Phoebe, he tells her "... when I expand you contract, when I contract you expand .." this is the same dialog Bruce Lee made in "Enter the Dragon" when he was explaining his technique to one of his masters near the beginning of the film.
Although the character's Anling, Yenlo and the Zen Master are supposed to be Chinese, they wield Japanese Katanas instead of Chinese Long Swords.
Here, the audience first sees Piper wearing reading glasses.