Perhaps you should try some spelling variations:
cau phuc » cau truc, chau phu, huu phuc
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
dan dai » dat dai, can dai, dan dat
phuc va » phuc vu, thuc va, chuc va
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
te sach » toc sach
ma hoi » mai hoi, xa hoi, ma hoa
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) or (te sach)) ky nang ma hoi. ((hieu ve) OR (hieu van)) cau phuc va dan dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang ma hoi. ((hieu ve) OR (hieu van)) cau phuc va dan dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang ma hoi. ((hieu ve) OR (hieu van)) cau phuc va dan dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang ma hoi. ((hieu ve) OR (hieu van)) cau phuc va dan dai cua tre*.