Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
toc sach » hoc sach, doc sach, thuoc sach
sang tay » sang tao, sang tai, sang tac
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
tay hoi » tay ho, tao hoi, tay thai
ky sang » ky nang, ky dang, ky tang
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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