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.
(..) You have an opportunity here, Bob. This is a rebirth. Now, if not for you, do it for your children. He just waltzes in and cuts in line? We reserve priority assistance for our Hilton Honors members. The promotions are great. You should check it out. Hungry much? Our business expense (..)2009 Up in the Air