He wrote the story with his friend's 'assistance'. = He wrote the story 'with the assistance of' his friend. [=his friend helped him to write the story]
Our family had to 'go on public assistance' [=receive money from the government] when my parents lost their jobs.
Nobody 'came to her assistance' [=nobody helped her] when her car broke down.
(..) Fix it, (horn honks/tires screech) (siren) (siren continues) (siren stops) Officer is requesting assistance on a California license plate ACU,,, (radio dispatcher) Roger, we copy request... Driver, step out of the car! Hey! Driver, step out of the car! (..)1994 The Glass Shield
(..) just keep the traffic flowing, Sir, I was the second officer on the scene, I'm sure I can be of some assistance, We don't need a Jewish mother tellin' us how to do our job, so you just move on, - (Baker) Bush! - Yes, sir? (..)1994 The Glass Shield