There are several different styles of drawer retainers and some of them have been mentioned here. If none of those work, feel along the back, top, edge of the drawer. Sometimes there is a vertical post that acts as a retainer. If so, some of them flip down to allow removal and others have to be physically removed (unscrewed).
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL