Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh doc » than doc, thanh do, nhanh doc
sinh cua » manh cua, dinh cuu, sinh va
vinh cuu » dinh cuu, dinh cu, tinh cua
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
lang ha » long ha
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
dang ha » dong ha, dung ha, tang ha
doc va » duoc va, hoc va, duc va

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) OR (lang ha)) hoi. hieu van 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) OR (lang ha)) hoi. hieu van thanh doc va hanh ((vinh cuu) OR (sinh cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((dang ha) OR (lang ha)) hoi. hieu van thanh doc va hanh ((vinh cuu) or (sinh cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((dang ha) OR (lang ha)) hoi. hieu van thanh doc va hanh ((vinh cuu) or (sinh cua)) tre*.