Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cua viet » ca viet, hoa viet, cua vat
va triet » va thiet, va trien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
vien cac » vien bach, vien dai, vien da
nang ma » tang ma, sang ma, nang cao
cac lop » cac hop, cac loai
nang xa » nang x, lang xa, mang xa
sac ky » cac ky, sai ky
lop va » lap va, hop va, nop va
su sac » su sach, su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky ((nang xa) OR (nang ma)) hoi. hieu vien cac lop va thanh vi ((va triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang xa) OR (nang ma)) hoi. hieu vien cac lop va thanh vi ((va triet) OR (cua viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky ((nang xa) OR (nang ma)) hoi. hieu vien cac lop va thanh vi ((va triet) or (cua viet))*".