Perhaps you should try some spelling variations:
hieu tien » hieu tieng, tieu tien, hieu hien
cua tre » cuu tre, cua triet, dua tren
tinh di » tinh doi, trinh di, tinh da
tac may » tao may, tac cay, tac xay
tien va » dien va, thien van
tu sach » thu sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa
va tac » va cac
cua te » cua tu

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 nang ma hoi. hieu tien va tac may tinh di ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ma hoi. hieu tien va tac may tinh di ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang ma hoi. hieu tien va tac may tinh di ((cua tre) OR (cua te))*".