Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
thanh ve » hanh ve, thanh va, thanh vien
hieu van » hieu va, thien van, lieu va
van tac » van thac, van tai, van tan
ty nang » ky nang, ty xang, ty hang
dat ban » bat ban, da ban, day ban
tac dat » tac da, tac dao, tac dau
sach ty » sach y, sach tu, sach thu
ve cua » le cua, de cua, te cua
me hoi » le hoi
ma hoi » mai hoi, ma hoa, va hoi

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 ty nang ((((ma hoi) or (me hoi))) or (xa hoi)). hieu van tac dat ban thanh ve cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((((ma hoi) OR (me hoi))) OR (xa hoi)). hieu van tac dat ban thanh ve cua vat.
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((((ma hoi) or (me hoi))) or (xa hoi)). hieu van tac dat ban thanh ve cua vat*.