Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
su sach » so sach, vu sach
nang ma » tang ma, sang ma, mang may
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
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: ((su sach) or (thu sach)) ky ((nang ma) OR (nang cao)) hoa. hieu ve cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) ky ((nang ma) OR (nang cao)) hoa. hieu ve cam xuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) ky ((nang ma) OR (nang cao)) hoa. hieu ve cam xuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) ky ((nang ma) OR (nang cao)) hoa. hieu ve cam xuc va hanh vi cua tre*.