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