Perhaps you should try some spelling variations:
hien cac » thien cac, hieu cac, dien cac
thu sach » thuat sach, thuoc sach, thu hoach
danh sai » dung sai, danh bat, danh dau
vien cac » vien bach, vien dai, vien da
sai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
tu sach » su sach, te sach, tu cach
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
lo va » lo van, lao va, ly va

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 (thu sach)) ty nang xa hoi. hieu ((hien cac) or (vien cac)) lo va danh sai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty nang xa hoi. hieu ((hien cac) OR (vien cac)) lo va danh sai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty nang xa hoi. hieu ((hien cac) or (vien cac)) lo va danh sai cua tre*.