Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
doi cua » dai cua, hoi cua
te sach » toc sach
ly vang » ly hang, ly van, ly quang
ly nang » ky nang, ly hang, ly quang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ly nang) or (ly vang)) xa hoi. hieu vien cac nuoc ((van hanh) OR (ban hanh)) doi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ly nang) OR (ly vang)) xa hoi. hieu vien cac nuoc ((van hanh) OR (ban hanh)) doi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ly nang) or (ly vang)) xa hoi. hieu vien cac nuoc ((van hanh) OR (ban hanh)) doi cua tu".
• Adding a wildcard symbol may retrieve word variants: te sach ((ly nang) or (ly vang)) xa hoi. hieu vien cac nuoc ((van hanh) OR (ban hanh)) doi cua tu*.