well In general, a reference is something that refers to something else, or acts as a connection or a link between two things. The objects it links may be concrete, such as books or locations, or abstract, such as data, thoughts, or memories. The object which is named by a reference, or to which the reference points, is the referent.
chronologicaal event sequence- well chronological means in order of which it happened, so that just means basically something which is in the right order,
cause and effect- i do know what it means, but ive forgotten,,
concessions means like when you go to the cinema or something, and you get money of if you are a concession. it just means discount.
and i hope that has helped! x