Perhaps you should try some spelling variations:
tinh van » trinh van, dinh van, tinh va
sach ly » sach lo, sach ty, sach hay
van cua » vang cua, ban cua, dan cua
duoc va » nuoc va, duc va, duoc ma
va cham » va chat, va tham
hieu va » lieu va, hieu qua
doc va » hoc va, duc va, loc va
hang o » hang do, hang o2, hoang o
cua su » qua su
o hoi » co hoi, o hoc, o hai

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) OR (sach y)) hang o hoi. hieu va cham ((doc va) or (duoc va)) tinh van cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ly) OR (sach y)) hang o hoi. hieu va cham ((doc va) OR (duoc va)) tinh van cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ly) OR (sach y)) hang o hoi. hieu va cham ((doc va) or (duoc va)) tinh van cua su".
• Adding a wildcard symbol may retrieve word variants: te ((sach ly) OR (sach y)) hang o hoi. hieu va cham ((doc va) or (duoc va)) tinh van cua su*.