Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
duc manh » suc manh, duc anh, duc tan
duc minh » duc anh
hanh dao » lanh dao, thanh dat, thanh dam
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
va pham » van pham, va phat, va phap
dao cua » dai cua, day cua, dan 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) or (tu sach)) ky nang xa hoi. lieu va pham ((duc manh) OR (duc minh)) hanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang xa hoi. lieu va pham ((duc manh) OR (duc minh)) hanh dao cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ky nang xa hoi. lieu va pham ((duc manh) OR (duc minh)) hanh dao cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky nang xa hoi. lieu va pham ((duc manh) OR (duc minh)) hanh dao cua tre*.