We specifically warn you against bringing anything that might make it appear as though you might be looking for work. Do not pack a resume or tools of your trade in your luggage. There are people who have been denied entry simply because they had a resume in their luggage. Hearty thanks to Gene for bringing our attention to the issue of denial of entry due to possession of a resume in the luggage of a tourist. First, these are two separate law enforcement agencies.
Immigration officers are concerned with people crossing a border.
Customs officers are concerned with things crossing a border. If both biological or adoptive parents are not traveling with a child, the parent must have a notarized letter from the absent parent giving permission for the child to travel with the parent. If the parent has sole custody or the other parent is deceased, the parent must carry papers proving those facts. Research this topic well in advance of your trip, as you may have to have these papers translated and consularized by local authorities. Fill yours out before leaving the aircraft, for convenience.