Perhaps you should try some spelling variations:
tinh van » trinh van, dinh van, tinh va
te sach » toc sach
sach ty » sach y, sach tu, sach thu
van cua » vang cua, ban cua, dan cua
duoc va » nuoc va, duc va, duoc ma
va chat » van chat, va phat, cao chat
va cham » va tham
ty hang » ly hang, ty xang, thi hang
loc va » hoc va, luc 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 ty hang o hoi. hieu ((va cham) or (va chat)) ((loc va) or (duoc va)) tinh van cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty hang o hoi. hieu ((va cham) OR (va chat)) ((loc va) OR (duoc va)) tinh van cua su.
• Adding a wildcard symbol may retrieve word variants: te sach ty hang o hoi. hieu ((va cham) or (va chat)) ((loc va) or (duoc va)) tinh van cua su*.