Who wrote Neil Armstrong's "One small step for man, one giant leap for mankind" quote?

Question

This is what Neil Armstrong said when I took his first step onto the moon. I know there is a small controversy about it being "One small step for a man.....". What I am interested in knowing is the name of the actual author of the statement.

Answer 1

Who else but Neil Armstrong?
I believe there was a blip in the original audio transmission, or in the person who transcribed it, that left out that "a".

Answer 2

It's always been my understanding that it was he who said it and no one else...that it wasn't scripted ot anything.

Answer 3

he did