Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
danh hoi » danh hoa, dan hoi, danh hoc
hieu ve » hieu van
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
hoi cua » hoi chuc
xuc va » duc va, tuc va, luc va
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: ((te sach) OR (toc sach)) ky nang x ho. ((hieu ve) or (hieu va)) cam xuc va danh hoi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x ho. ((hieu ve) OR (hieu va)) cam xuc va danh hoi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang x ho. ((hieu ve) or (hieu va)) cam xuc va danh hoi cua tu".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang x ho. ((hieu ve) or (hieu va)) cam xuc va danh hoi cua tu*.