Perhaps you should try some spelling variations:
chat thien » phat trien, cai thien, phat hien
hieu van » hieu va, thien van, lieu va
hanh lam » thanh lap, hanh kem, hanh va
lam chat » luan chat, cao chat, ly chat
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
duc van » duc va, duc manh, duc phan
sac ky » cac ky, sai ky

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) OR (sac ky)) nang xa hoi. hieu van cac ((duc van) or (duc tan)) hanh lam chat thien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cac ((duc van) OR (duc tan)) hanh lam chat thien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cac ((duc van) or (duc tan)) hanh lam chat thien".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cac ((duc van) or (duc tan)) hanh lam chat thien*.