Perhaps you should try some spelling variations:
chuan quoc » han quoc, phan quoc, chua nuoc
sach benh » bach benh, mach benh, sach kinh
cua triet » cua viet, su triet, va triet
cua quoc » cua nuoc, cua thuoc
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) OR (cua quoc)) sach 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) OR (cua quoc)) sach benh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y lang xa hoi. hieu va ((chuan quoc) OR (cua quoc)) sach 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) OR (cua quoc)) sach benh vi ((cua tre) or (cua triet))*.