Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hoc sach » hoc sinh, hoc cac, hoc anh
va thanh » gia thanh, va tinh, le thanh
dang mai » dang hai, dang mau, dang bai
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
mai hoi » mai khoi, dai hoi, lai hoi
ky dang » ky nang, ky danh

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky dang mai hoi. hieu van cam xuc ((va thanh) OR (ban thanh)) ((vai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky dang mai hoi. hieu van cam xuc ((va thanh) OR (ban thanh)) ((vai cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky dang mai hoi. hieu van cam xuc ((va thanh) OR (ban thanh)) ((vai cua) or (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky dang mai hoi. hieu van cam xuc ((va thanh) OR (ban thanh)) ((vai cua) or (lai cua)) tre*.