Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
duc manh » suc manh, duc anh, duc minh
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc phan
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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

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