Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
quoc bao » quoc oai, hoc bao, quoc va
hieu van » hieu va, thien van, lieu va
cua tre » cuu tre, cua triet, dua tren
benh te » benh tre, benh ve, benh he
quoc bo » nuoc bo, quoc co, quoc lo
van lam » van nam
lang xa » lang ha, dang xay, lang van
sach o » sach lo, sac o, sach y
o lang » hoa lang, hoi lang
cua te » cua tu

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 o lang xa hoi. hieu van lam ((quoc bo) OR (quoc bao)) benh te ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach o lang xa hoi. hieu van lam ((quoc bo) OR (quoc bao)) benh te ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach o lang xa hoi. hieu van lam ((quoc bo) OR (quoc bao)) benh te ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach o lang xa hoi. hieu van lam ((quoc bo) OR (quoc bao)) benh te ((cua tre) or (cua te))*.