Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
ban benh » san benh, ba benh, ban banh
quoc ban » quoc bao, quoc lan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
cua tre » cua te, cuu tre, dua tren
benh vi » benh va, benh ve, benh li
sach ky » sac ky, sach y, sach kem
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
van cam » van nam, van lam, van cau

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 ky) or (sach ty)) nang xa hoi. hieu van cam quoc ban benh vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu van cam quoc ban benh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach ty)) nang xa hoi. hieu van cam quoc ban benh vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang xa hoi. hieu van cam quoc ban benh vi ((cua tre) OR (cua triet))*.