Perhaps you should try some spelling variations:
hoc quoc » hoc nuoc, hoc duoc, hoc thuoc
tu sach » thu sach, su sach, te sach
dao bai » cao bai, dao hai, dao lai
cua tre » cua te, cua triet, dua tren
dao lam » da lam, dao nam, dat lam
quoc va » nuoc va, duoc va, quoc gia
qua hoc » cua hoc, quang hoc, qua hoat
lang xa » lang ha, dang xay, lang van
cuu tre » cau tren, cau treo
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y lang xa hoi. hieu qua hoc quoc va ((dao lam) or (dao bai)) ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu qua hoc quoc va ((dao lam) OR (dao bai)) ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu qua hoc quoc va ((dao lam) or (dao bai)) ((cua tre) or (cuu tre))*.