In this task, you are given a list. This list contains many lists of integers. The list is several items written within a []. Your task is to find the maximum number among the members of each inner list. The output should be a list comprised of the maximums with the same order as the internal lists.
[[23, -11, -135, -20], [-71, -7, 42], [-89, -116], [-148, 31, 39, -159, -28, 97, -4]]