Perhaps you should try some spelling variations:
chuan quoc » han quoc, cua quoc, phan quoc
cua triet » cua viet, su triet, va triet
va chuan » va chan, va chua, va huan
quoc sau » quoc su, quoc suu, quoc sach
sau benh » san benh, phau benh, tai benh
te sach » toc sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
benh vi » benh va, benh ve, benh li
cua tre » cua te, cuu tre, dua tren
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: te sach y lang xa hoi. hieu va chuan quoc sau benh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y lang xa hoi. hieu va chuan quoc sau benh vi ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: te sach y lang xa hoi. hieu va chuan quoc sau benh vi ((cua tre) or (cua triet))*.