Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
dinh hai » dinh thai, dinh ha, dinh tai
tinh hai » tinh thai, tinh chat, trinh han
vien dai » hien dai
te sach » toc sach
dai lao » dai lan, dai thao, dai luan
nang xa » nang x, lang xa, nang ma
lao va » tao va, cao va, bao va
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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 v nang xa hoi. hieu vien dai lao va ((dinh hai) or (tinh hai)) ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang xa hoi. hieu vien dai lao va ((dinh hai) OR (tinh hai)) ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang xa hoi. hieu vien dai lao va ((dinh hai) or (tinh hai)) ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: te sach v nang xa hoi. hieu vien dai lao va ((dinh hai) or (tinh hai)) ((cua tu) OR (cua su))*.