John Lennon: "I was sick of White Christmas" | Music | guardian.co.uk:
"Then there's a song he and the Plastic Ono Band will be recording that very night, for their Christmas single. It's called Happy Christmas (War Is Over), and he says that when he first played it to Spector, the producer said that the first line is a direct crib from the Paris Sisters' I Love How You Love Me, which Phil produced back in the pre-Crystals days.

"'I like quoting from old songs,'" John says, "'but you get into such trouble with copyrights. It's a drag.'"