Perhaps you should try some spelling variations:
thanh loi » thanh hoa, thanh hai, thanh lap
chat duc » chat xuc, chat doc, chet duoc
hanh tai » thanh tai, hang tai, han tai
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
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: su sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chat duc van ((thanh loi) or (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chat duc van ((thanh loi) OR (hanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chat duc van ((thanh loi) or (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chat duc van ((thanh loi) or (hanh tai)) cua tre*.