Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh van » doan van, doanh va, doanh ban
doc sach » hoc sach, toc sach, nuoc sach
tru lang » tre lang, tru nang, tu lang
lang xa » lang ha, dang xay, lang van
qua cao » qua cac, qua ca, qua cai
van cua » vang cua, ban cua, dan cua
suc va » tuc va, luc va, soc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) or (doc sach)) tru lang xa hoi. hieu qua cao ((suc va) OR (duc va)) doanh van cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (doc sach)) tru lang xa hoi. hieu qua cao ((suc va) OR (duc va)) doanh van cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (doc sach)) tru lang xa hoi. hieu qua cao ((suc va) OR (duc va)) doanh van cua te".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (doc sach)) tru lang xa hoi. hieu qua cao ((suc va) OR (duc va)) doanh van cua te*.