Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
doc sach » hoc sach, nuoc sach, dac sac
ty lang » tay lang, ty xang, ty hang
lang ha » long ha
hieu va » lieu va, hieu qua
ha hoi » hoa hoi, ha noi, xa hoi
cac tu » cac thu, cach tu, cac du
tu van » tu va
cua tu » cua tuc, cua su, cua cu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty lang ha hoi. hieu va cac tu van hanh vi ((cua te) OR (cua tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty lang ha hoi. hieu va cac tu van hanh vi ((cua te) or (cua tu))~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty lang ha hoi. hieu va cac tu van hanh vi ((cua te) or (cua tu))*.