Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hai, thanh loi
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
nam hoc » nam moc, nam hoi, am hoc
y nang » ky nang, ly nang, v nang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang xa hoi. hieu van nam hoc dan ((thanh hoi) or (((thanh hoa) OR (thanh pho)))) cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. hieu van nam hoc dan ((thanh hoi) OR (((thanh hoa) OR (thanh pho)))) cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang xa hoi. hieu van nam hoc dan ((thanh hoi) or (((thanh hoa) OR (thanh pho)))) cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. hieu van nam hoc dan ((thanh hoi) or (((thanh hoa) OR (thanh pho)))) cua tu*.