The World’s Prayer Guide (CT) "Operation World might just be one of the most popular and influential evangelical books you've never read. Since 1974, the daily, country-by-country prayer guide has sold 2.5 million copies in six editions, including about 400,000 for the 2001 (most recent) edition. Canadian Jason Mandryk, a missionary researcher with Worldwide Evangelization for Christ International, has taken the reins as author of the newest edition, which will be published next month..."