The following article was found in one Adventist publication:
THE MODERN ADVENTIST’S VERSION OF THE TRINITY:
Arthur S. Maxwell: "Do Seventh-day Adventists believe in the Trinity? They do. Reverently they worship Father, Son, and Holy Spirit. ‘three Persons in one God. And they do so because they believe this to be the teaching of the Bible concerning God in His relation to this world and the human race." A Guide to the Religions of America, by Leo Rosten, p.136. What is a Seventh-day Adventist? By Arthur S. Maxwell