Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
hieu van » hieu va, thien van, lieu va
toc gia » toc giay, tac gia, quoc gia
lam toc » lam thuoc, lam truoc, lam duoc
van lam » van nam
vu sach » vu bach, su sach, vu khach
cua tuc » cua duc, cua thuoc, luat tuc
sach ky » sac ky, sach y, sach ty
so hoc » co hoc, mo hoc, so hoa
cua tu » cua su, cua cu, cua te
o hoi » co hoi, o hoc, o hai

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

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