Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
su sach » so sach, vu sach
va danh » va dinh, va dan, va hanh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
sach ky » sac ky, sach y, sach ty
xa danh » dia danh, nam danh, van danh
cac tuc » cac toc, cac tu, cac tac
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ma hoi. hieu vien cac tuc ((xa danh) OR (va danh)) doi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. hieu vien cac tuc ((xa danh) OR (va danh)) doi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. hieu vien cac tuc ((xa danh) OR (va danh)) doi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu vien cac tuc ((xa danh) OR (va danh)) doi ((cua tre) or (cuu tre))*.