Complex sentence: This was the third SEA Games to be hosted by the Philippines with the last two held in 1981 (see 1981 Southeast Asian Games) and 1991 (see 1991 Southeast Asian Games).
Split into simpler sentences: This was the third SEA Games to be hosted by the Philippines. The last two times the Philippines hosted the games were in 1981 (see 1981 Southeast Asian Games), and again in 1991 (see 1991 Southeast Asian Games).