Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
van lam » van nam
sach ky » sac ky, sach y, sach ty
duoc va » nuoc va, duc va, duong va
duoc ma » duoc lam
danh va » doanh va, hanh va, anh va
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi
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: toc sach ky lang ha hoi. hieu van lam ((duoc va) or (duoc ma)) danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang ha hoi. hieu van lam ((duoc va) OR (duoc ma)) danh va cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang ha hoi. hieu van lam ((duoc va) or (duoc ma)) danh va cua tre*.