Perhaps you should try some spelling variations:
hoc quoc » hoc nuoc, hoc duoc, hoc thuoc
than cua » nhan cua, ban cua, gian cua
thai cua » tai cuc, tri cua, dai cua
hieu van » hieu va, thien van, lieu va
va dang » van dang, va nang, va lang
quoc va » nuoc va, duoc va, quoc gia
van hoc » van hoa
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ky) OR (sac ky)) nang xa hoi. hieu van hoc quoc va dang ((thai cua) or (than cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sac ky)) nang xa hoi. hieu van hoc quoc va dang ((thai cua) OR (than cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) OR (sac ky)) nang xa hoi. hieu van hoc quoc va dang ((thai cua) or (than cua)) te".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ky) OR (sac ky)) nang xa hoi. hieu van hoc quoc va dang ((thai cua) or (than cua)) te*.