Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
hieu van » hieu va, thien van, lieu va
van nang » van quang, van ban, van dong
tang van » dang van, hoang van, trong van
nang van » dang van, lang van, nong van
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
va dinh » van dinh, va kinh, va tinh
te sach » toc sach
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang van) OR (tang van)) hoe. hieu van nang luc ((va hanh) or (va dinh)) va dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang van) OR (tang van)) hoe. hieu van nang luc ((va hanh) OR (va dinh)) va dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang van) OR (tang van)) hoe. hieu van nang luc ((va hanh) or (va dinh)) va dau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang van) OR (tang van)) hoe. hieu van nang luc ((va hanh) or (va dinh)) va dau tren*.