Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
va doanh » van doanh, vay doanh, hoa doanh
tai cua » thai cua, tai cuc, tri cua
va danh » va dinh, va dan, va hanh
hoi hoi » hoi hoc, hoc hoi, hoi doi
sach ky » sac ky, sach y, sach ty
van am » van nam, van lam, van dam
ho hoi » hoc hoi, hoa hoi, co hoi
cua te » cua tu

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 nang ((ho hoi) OR (hoi hoi)). hieu van am thuc ((va doanh) or (va danh)) tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ((ho hoi) OR (hoi hoi)). hieu van am thuc ((va doanh) OR (va danh)) tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang ((ho hoi) OR (hoi hoi)). hieu van am thuc ((va doanh) or (va danh)) tai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((ho hoi) OR (hoi hoi)). hieu van am thuc ((va doanh) or (va danh)) tai cua te*.