Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cua triet » cua viet, su triet, va triet
vien cac » vien bach, vien dai, vien da
van nang » van quang, van ban, van dong
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
cac thu » cach thuc, cac thoi
vu nang » vuc nang, va nang, vu dang
thu va » thuc va, thue va, tu va
thiet » thieu

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 ((van nang) or (vu nang)) xa hoi. hieu vien cac thu va hanh di ((cua triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((van nang) OR (vu nang)) xa hoi. hieu vien cac thu va hanh di ((cua triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: su sach ((van nang) or (vu nang)) xa hoi. hieu vien cac thu va hanh di ((cua triet) or (va thiet))*.