Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
duc manh » suc manh, duc anh, duc minh
hanh via » hanh vi, hanh va, anh va
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc phan
via cua » gia cua, gian cua, giau cua
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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 (thuat sach)) ky nang x hoi. hieu ve cac ((duc van) OR (duc manh)) hanh via cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ky nang x hoi. hieu ve cac ((duc van) OR (duc manh)) hanh via cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuat sach)) ky nang x hoi. hieu ve cac ((duc van) OR (duc manh)) hanh via cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuat sach)) ky nang x hoi. hieu ve cac ((duc van) OR (duc manh)) hanh via cua tre*.