Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
van khanh » van thanh, van anh, van phan
van hanh » van thanh, ban hanh, van anh
cac truc » cau truc, cac trung, sach truc
su sach » so sach, vu sach
su tien » su kien, su hien, tu tieng
cac tru » ca tru, cac tro, cac thu
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
di su » doi su, ki su, da su

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 v nang x hoi. hieu vien ((cac truc) or (cac tru)) ((van khanh) OR (van hanh)) di su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang x hoi. hieu vien ((cac truc) OR (cac tru)) ((van khanh) OR (van hanh)) di su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang x hoi. hieu vien ((cac truc) or (cac tru)) ((van khanh) OR (van hanh)) di su tien".
• Adding a wildcard symbol may retrieve word variants: su sach v nang x hoi. hieu vien ((cac truc) or (cac tru)) ((van khanh) OR (van hanh)) di su tien*.