First, read the English article below.

Use a pair of sharp pruning shears to snip the lower end of the stem at a slight angle. Only take healthy cuttings that do not have signs of disease of infestation. Cutting the stem at an angle increases its surface area, allowing it to take up more moisture and nutrients from the planting soil.  Wear gardening gloves and eye protection when you take a cutting. Take semi-ripe or hardwood for your cuttings rather than younger sections that are still green. The best time to take cuttings from bougainvillea is late-spring to mid-summer, when growth is most rapid and abundant. Getting bougainvillea to root can be tricky. Consider taking multiple cuttings to give yourself more than one shot if your first attempt fails. You can cut back as much as a third of the plant's growth without worrying about harming it. Sterilize your gardening tools with rubbing alcohol before and after you take a cutting. The stem is the only part of the bougainvillea that will  take root successfully. Cut away all flowers, leaves, and small offshoots from the slender, woody shaft. Trim and discard any sections that are still green, as these are less likely to survive when planted.  Make sure you remove at least half of the leaves from the stem. This will help ensure that all of the plant’s resources are being used to form new roots. If you’re not planning on rooting your bougainvillea right away, wrap your cuttings in a damp paper towel and store them in the refrigerator in an airtight plastic bag. This will keep them from drying out for 1-2 weeks. Wet the bottom of the stem and press it into a container of powdered rooting hormone. Coat the underside thoroughly, but avoid caking or clumping. To remove excess powder, tap the stem lightly with your fingertip.  Rooting hormone can be found at most major gardening centers, greenhouses, and plant nurseries. It’s also sometimes known as “rooting acid.” You can also try making your own rooting hormone at home using ingredients like apple cider vinegar, cinnamon, honey, or crushed Aspirin. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Cắt một đoạn cành trưởng thành dài khoảng 15-20 cm. Tỉa bỏ lá trên đoạn cành. Nhúng đầu cắt vào bột hoóc môn kích thích ra rễ.