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.
(..) Forget it. Sometimes I feel like a piece of meat. That was all I knew. Sorry, you have even? Excuseer me a while, my mug partner will provide further assistance. Sorry, I am too late. - Is he a lawyer? Madam, I was already a bloodsucker, I had only a aktekoffer needed. Another fine day ahead. (..)2007 Bee Movie