Perhaps you should try some spelling variations:
chat luc » chat xuc, chat lua, nhan luc
van hanh » van thanh, ban hanh, van anh
mai hoi » mai khoi, dai hoi, lai hoi
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
luc van » luoc van, luu van, duc van
hanh le » thanh le, hanh ve, hanh de
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
le cua » ly cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ky) OR (sac ky)) nang ((xa hoi) or (mai hoi)). hieu ve chat luc van hanh le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sac ky)) nang ((xa hoi) OR (mai hoi)). hieu ve chat luc van hanh le cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) OR (sac ky)) nang ((xa hoi) or (mai hoi)). hieu ve chat luc van hanh le cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) OR (sac ky)) nang ((xa hoi) or (mai hoi)). hieu ve chat luc van hanh le cua tre*.