Amos 2014 Study Study Text Audio Video Amos 1-2 Text Audio Video Amos 3-4 Text Audio Video Amos 5 Text Audio Video Amos 6-7 Text Audio Video Amos 8-9 Text Audio Video 2006 Study Study Text Audio Amos 1-3 Text N/A Amos 4-5 Text N/A Amos 6-9 Text N/A