Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu cac » hieu luc, hieu va, hieu van
danh dai » danh dau, danh di, doanh dao
vanh dai » van dai, vanh tai, lanh dao
danh sai » dung sai, danh bat, danh dau
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac cau » cac mau, bac cau, ca cau
truc va » thuc va, thuc vat, trung va
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 xa hoi. hieu cac cau truc va ((((danh dai) OR (vanh dai))) or (danh sai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. hieu cac cau truc va ((((danh dai) OR (vanh dai))) OR (danh sai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. hieu cac cau truc va ((((danh dai) OR (vanh dai))) or (danh sai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. hieu cac cau truc va ((((danh dai) OR (vanh dai))) or (danh sai)) cua tre*.