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
quoc bo » quoc bao, quoc co, quoc lo
nuoc bo » nuoc bao, nuoc bot, nuoc o
benh te » benh tre, benh ve, benh he
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
va lam » van lam, va lap
te cua » tue cua, le 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 y lang xa hoi. hieu va lam ((quoc bo) or (nuoc bo)) benh te cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. hieu va lam ((quoc bo) OR (nuoc bo)) benh te cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. hieu va lam ((quoc bo) or (nuoc bo)) benh te cua tre*.