Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cai
va cao » va cac, va co, va dao
xuc va » duc va, tuc va, luc 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: ((toc sach) OR (doc sach)) ky nang ma hoi. hieu ((va cam) or (va cao)) xuc va hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang ma hoi. hieu ((va cam) OR (va cao)) xuc va hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ky nang ma hoi. hieu ((va cam) or (va cao)) xuc va hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ky nang ma hoi. hieu ((va cam) or (va cao)) xuc va hanh vi cua vat*.