Article in English: If you want the girl to miss you when you're not together, then you can't spend too much of your free time with her. You should hang out with her enough to make her see how awesome, fun, and interesting you are, but not so much that she starts to take you for granted or feels like you've run out of things to say to each other. Make an effort to see her once or twice a week, but make sure she's not the only thing on your social calendar, or she'll begin to think that she can have you whenever she wants.  If she wants to hang out with you, she should make plans with you at least a few days in advance. You don't want it to look like you're at her beck and call.  When you do hang out with her, don't spend the entire day with her, but leave to do something else after a few hours so she really relishes the time you do spend together instead of getting too comfortable with you. This may feel a little strange, at first, but hey, it's part of playing hard to get. If you and the girl you like talk on the phone, make sure you keep your conversations relatively short so she doesn't think you have nothing better to do than to talk to her all the time. You can talk to her to set up plans or to see how she's doing for a few minutes, but you shouldn't let the conversation drag on so long that you've run out of things to say. To keep her interested, you want her feel like she can never run out of things to say to you.  Don't tell her everything that you're thinking or everything that's going on in your life over the phone. Save some of it for when you actually hang out in person. Make the time count. If you only talk to her on the phone for a few minutes, make sure you bring your A game and charm her, make her laugh, and make her feel special. Don't talk to her while also watching the Jets game; make her feel like you do value your conversations. To make a girl miss you, you can't make her feel like you're at her beck and call. If she texts you and you're busy, don't go out of your way to give her a lengthy response ASAP,...

Summary in Vietnamese:
Hạn chế lượng thời gian hai bạn ở cạnh nhau. Hạn chế thời gian gọi điện thoại. Đừng bỏ mọi thứ để trò chuyện với cô ấy. Tiếp tục theo đuổi những sở thích của bạn. Tiếp tục dành thời gian cho bạn bè. Khiến cô ấy phải suy đoán.