It sounds like they are most likely referring to a shoulder press of some sort. Here is what ExRx.net has on the subject:
Dumbbell shoulder press
Instructions
Preparation
Position dumbbells to each side of shoulders with elbows below wrists.
Execution
Press dumbbells until arms are extended overhead. Lower and repeat.
Barbell military press
Instructions
Preparation
Grasp barbell from rack or clean barbell from floor with overhand grip, slightly wider than shoulder width. Position bar in front of neck.
Execution
Press bar until arms are extended overhead. Lower to front of neck and repeat.
Or maybe dumbbell press can mean this:
DB chest press
Preparation
Sit down on bench with dumbbells resting on lower thigh. Kick weights to shoulder and lie back. Position dumbbells to the sides of the upper chest with elbows under dumbbells.
Execution
Press dumbbells up with elbows to the sides until arms are extended. Lower weight to the sides of the upper chest. Repeat.
So it sounds like the book you were reading was
probably referring to a military press - type exercise, although they were a bit vague about it. First of all, "targetting upper pecs" makes that book very suspect. What book did you get that from?