Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
hanh va » hanh vi
tuc ban » thuc ban, truc ban, tu ban
cam tuc » cam xuc, cam tu, nam thuc
van cam » van nam, van lam, van cau
lang xa » lang ha, dang xay, lang van
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: toc sach y ((lang xa) or (hang va)) hoi. hieu van cam tuc ban hanh va ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((lang xa) OR (hang va)) hoi. hieu van cam tuc ban hanh va ((cua tu) OR (cua su))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y ((lang xa) or (hang va)) hoi. hieu van cam tuc ban hanh va ((cua tu) OR (cua su))*".