Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
nam thuc » nam thuoc, nam thu, nam tu
cau treo » cau theo, cau tren, cau triet
hoc sach » hoc sinh, hoc cac, hoc anh
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
dau vai » dau va, dau hai, dau tai
vai cau » va cau, van cau, vai cac
hieu va » lieu va, hieu qua
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (hoc sach)) ky dang xa hoi. hieu va ((nam thuc) or (am thuc)) va dau vai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky dang xa hoi. hieu va ((nam thuc) OR (am thuc)) va dau vai cau treo.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ky dang xa hoi. hieu va ((nam thuc) or (am thuc)) va dau vai cau treo*.