Perhaps you should try some spelling variations:
tinh tai » trinh tai, tinh thai, tinh hai
dang mau » dong mau, dang van, dang su
tu sach » thu sach, te sach, tu cach
va tinh » may tinh
cac luc » cau luc, coc luc, cac nuoc
hieu va » lieu va, hieu qua
hieu ve » hieu van
mau hoi » cau hoi, mai hoi, mau ho
ky dang » ky nang, ky danh
su sach » so sach, vu sach
cuc tre » duc tre, cua tre, cuu tre
luc va » duc va, tuc va, loc va

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 (su sach)) ky dang mau hoi. ((hieu ve) OR (hieu va)) cac luc va tinh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky dang mau hoi. ((hieu ve) OR (hieu va)) cac luc va tinh tai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky dang mau hoi. ((hieu ve) OR (hieu va)) cac luc va tinh tai cuc tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky dang mau hoi. ((hieu ve) OR (hieu va)) cac luc va tinh tai cuc tre*.