Perhaps you should try some spelling variations:
manh hai » lanh hai, minh hai, thanh hai
ban manh » ban hanh, van manh, ban mach
hai cua » thai cua, dai cua, hoi cua
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
hieu va » lieu va
lang xa » lang ha, dang xay, lang van
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sac ky)) lang xa hoi. ((hieu va) OR (hieu qua)) cam duc ban manh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) lang xa hoi. ((hieu va) OR (hieu qua)) cam duc ban manh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) lang xa hoi. ((hieu va) OR (hieu qua)) cam duc ban manh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) lang xa hoi. ((hieu va) OR (hieu qua)) cam duc ban manh hai cua tre*.