Perhaps you should try some spelling variations:
sach chuc » cach thuc, sach che, sach thu
doc sach » hoc sach, toc sach, nuoc sach
duc manh » suc manh, duc anh, duc minh
hanh lai » hanh lam, hanh tai, thanh lap
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
duc van » duc va, duc phan, duc hanh
lai cua » dai cua, hai cua, lai chau
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: doc sach chuc nang xa hoi. hieu va cac ((((duc van) OR (duc manh))) or (duc tan)) hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach chuc nang xa hoi. hieu va cac ((((duc van) OR (duc manh))) OR (duc tan)) hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach chuc nang xa hoi. hieu va cac ((((duc van) OR (duc manh))) or (duc tan)) hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: doc sach chuc nang xa hoi. hieu va cac ((((duc van) OR (duc manh))) or (duc tan)) hanh lai cua tre*.