Perhaps you should try some spelling variations:
cao suc » cao su
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
cao duc » dao duc, giao duc, tao duoc
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
va anh » van anh, va danh, va hanh
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua
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: thuat ((sach ky) OR (sac ky)) nang x hoi. hieu ve ((cao duc) or (cao suc)) va anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sac ky)) nang x hoi. hieu ve ((cao duc) OR (cao suc)) va anh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) OR (sac ky)) nang x hoi. hieu ve ((cao duc) or (cao suc)) va anh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ky) OR (sac ky)) nang x hoi. hieu ve ((cao duc) or (cao suc)) va anh vi cua tre*.