Combining Automatic and Manual Approaches: Towards a Framework for Discovering Themes in Disaster-related Tweets. - Leif Romeritch Syliongka; Alron Jan Lam; Cheryll Ruth Soriano; Ma. Divina Gracia Roldan; Francisco Magno; Charibeth Ko Cheng; Nathaniel Oco (WWW (Companion Volume), 2015)