Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
cam tuc » cam xuc, cam tu, dam thuc
hieu ve » hieu va, hieu van
ty nang » ky nang, ty hang, ly nang
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty nang) or (ty xang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ty xang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vai cuu tre*.