Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
thanh va » thanh van, hanh va, thanh ha
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky ((nang xa) OR (nang ma)) hoi. hieu van pham duc ban thanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky ((nang xa) OR (nang ma)) hoi. hieu van pham duc ban thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang xa) OR (nang ma)) hoi. hieu van pham duc ban thanh va cua tre*.