Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cham loc » cham soc, chon loc, hau loc
van nang » van quang, van ban, van dong
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, voi nang
cham o » cham soc
va dao » ca dao
dao do » dao o, dao ho, do do
do cua » doi cua, co cua, de cua

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 ((v nang) or (van nang)) xa hoi. hieu van ((cham loc) or (cham o)) va dao do cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((v nang) OR (van nang)) xa hoi. hieu van ((cham loc) OR (cham o)) va dao do cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((v nang) or (van nang)) xa hoi. hieu van ((cham loc) or (cham o)) va dao do cua tre*.