Perhaps you should try some spelling variations:
chat thien » phat trien, cai thien, phat hien
thu sach » tu sach, thuat sach, thuoc sach
hanh lam » thanh lap, hanh va, dinh lam
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
duc van » duc va, duc manh, duc phan
ve cac » va cac, vien cac

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