Karen Matthews co-authored the study with Lewis Kullers.卡伦·马修斯与刘易斯·库勒斯合作完成了这个研究课题。Robert and his daughter have co-authored a diet book specifically written for young women.罗伯特跟他女儿一起写了一本有关健康饮食的书，阅读对象是年轻女性。He's co-authored a book on Policy for Tourism.他与人合著了一本有关旅游业政策的书。