Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
nang mai » nang ma, nang tai, lang mai
tu sach » thu sach, te sach, tu cach
va tinh » may tinh
vien va » dien va, vien da, tien va
mai hoi » mai khoi, dai hoi, lai hoi
su sach » so sach, vu sach
va tuc » va thuc, va tu, va tac
tuc va » thuc va, truc va, tuc xa
di cuu » di cua, dinh cuu
di cau » da cau, diem cau

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