Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
hieu van » hieu va, thien van, lieu va
trang xa » trang va, trang ha, trong xa
sach ky » sac ky, sach y, sach kem
van cam » van nam, van lam, van cau
sach ty » sach y, sach tu, sach thu
duc ban » duc tan, duc van, dua ban
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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