Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
vat cuu » vat cua
dan vat » dang vat, van vat, dan va
cam tuc » cam xuc, cam tu, dam thuc
hieu ve » hieu va, hieu van
ty hang » ly hang, thi hang, thu hang
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 xang) or (ty hang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty xang) OR (ty hang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vat cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty xang) or (ty hang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vat cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty xang) or (ty hang)) xa hoi. hieu ve ((cam tuc) OR (nam thuc)) va dan vat cuu tre*.