Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
ve cac » va cac, vien cac
va dan » ca dan, va dau, va dap
va dao » ca dao

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 sang mai hoi. hieu ve cac xuc ((va hanh) or (((va dan) OR (va dao)))) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang mai hoi. hieu ve cac xuc ((va hanh) OR (((va dan) OR (va dao)))) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang mai hoi. hieu ve cac xuc ((va hanh) or (((va dan) OR (va dao)))) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang mai hoi. hieu ve cac xuc ((va hanh) or (((va dan) OR (va dao)))) hai cua tre*.