I am conducting research on children of migrant parents and want to include children of parents who are legally resident in the country as opposed to illegal immigrants. This is for protection purposes as illegal migrants may fear to participate because of their illegal status. As this is a study of children, I have to go through their parents, so the status of the children is of no concern as it is dependent on the parents' status. For the legal migrants, how can I know about their legal status without actually asking for their documentation, which I feel is too intrusive? Is there another way to recruit legal migrants without asking about their status? I would appreciate any other ways to recruit only legal migrants that you have experienced. Thanks in advance.