Complex sentence: As from 1972 Jan Snijders acted as a referee, firstly national, then as from 1976 continental (E.J.U.) and as from 1984 international (I.J.F.).
Split into simpler sentences: As from 1972 Jan Snijders acted as a referee. Firstly national, as from 1976 continental (E.J.U.) and as from 1984 internationally (I.J.F.).