Perhaps you should try some spelling variations:
hieu thien » chieu chien, dieu khien, bieu hien
hieu hien » bieu hien, dieu hien, chieu chien
hach xuc » thach duc, hanh xu, cach xu
tu sach » thu sach, te sach, tu cach
tinh va » tich va, trinh van, trinh vat
va tinh » may tinh
chu tre » cho tre, chu tri, cuu tre
su sach » so sach, vu sach
xuc va » duc va, tuc va, luc va
va chu » va che, va cau, va chi
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: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu thien) or (hieu hien)) hach xuc va tinh va chu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu thien) OR (hieu hien)) hach xuc va tinh va chu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang x hoi. ((hieu thien) or (hieu hien)) hach xuc va tinh va chu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu thien) or (hieu hien)) hach xuc va tinh va chu tre*.