How long have you been working out consistently? Do you have a good routine or following a program? Are you pushing yourself hard enough when you work out? Do you track your food/ calories daily? If you aren't doing any of these, don't expect good resluts. Stomach fat is going to be stubburon, and depending on what results you want it can take a lot of time and dedication.
You need to burn the fat so you have to make work yours biggest muscles.
You can also do full body workout or hiit program
If you want to have a lot of fun try this
LET'S FINISH THIS - BOXING *Sk
A very efficient one is
CONQUER THE MOUNTAIN*Sk
By the way you need also to have a clean diet, and it means you don't stop eating. Some people stop eating and it's a mistake! If your body starve it will keep as much fat it could when it has the possibility. So train hard eat clean and you will reach your goal!