Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
hanh di » hanh de, hang di, danh di
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
luc va » duc va, tuc va, loc va

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 hoi. hieu va cac luc va ((hanh di) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. hieu va cac luc va ((hanh di) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. hieu va cac luc va ((hanh di) or (hanh vi)) cua tre*.