MOS Study Guide for Microsoft Office 365 Author:John Pierce Demonstrate your expertise with Microsoft Office 365 by earning a MOS certification. This Study Guide is designed to help you prepare for MOS Exam 77-891: Microsoft Office 365, and features: — Full objective-by-objective review Easy-to-follow procedures and hands-on tasks Exam-discount offer from Certiport Use the in-depth exam prep, practice, a... more »nd review to help advance your proficiency with Office 365?and earn the credential that proves it.« less