Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh doc » than doc, thanh do, nhanh doc
thien ban » thien bang, thien van, phien ban
sinh cua » manh cua, dinh cuu, sinh va
vinh cuu » dinh cuu, dinh cu, tinh cua
toc sach » hoc sach, doc sach, thuoc sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
ky dang » ky nang, ky danh
doc va » duoc va, hoc va, duc va
ha hoi » hoa hoi, xa hoi, 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: toc sach ky dang ((ha hoi) or (ha noi)). thien ban thanh doc va hanh ((vinh cuu) or (sinh cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang ((ha hoi) OR (ha noi)). thien ban thanh doc va hanh ((vinh cuu) OR (sinh cua)) tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang ((ha hoi) or (ha noi)). thien ban thanh doc va hanh ((vinh cuu) or (sinh cua)) tre*.