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 ready? Move Louis. Officer down, officer down, Hamilton. This is detective Alex Murphy in need of immediate medical assistance. Hamilton Road. "Jack." "Jack," come on "Jack," Do you hear me? "Jack," Stay with me. (..)2014 RoboCop