Complex sentence: Other great sources include official government documents or publications, or information from a news agency, if it is one which is highly reputable, such as BBC, a news sourced used in the article on the Iranian Embassy seige.
Split into simpler sentences: Other great sources include official government documents or publications, or information from a news agency. Use those that are highly reputable, such as BBC, a news source used in the article on the Iranian Embassy seige.