Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
te sach » toc sach
nam luc » nang luc, nhan luc, nam thuc
van hoe » van hoa, van hoc, van hieu
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
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 ((y lang) OR (_ lang)) van hoe. hieu van nam luc ((va danh) or (va hanh)) va dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((y lang) OR (_ lang)) van hoe. hieu van nam luc ((va danh) OR (va hanh)) va dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((y lang) OR (_ lang)) van hoe. hieu van nam luc ((va danh) or (va hanh)) va dau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ((y lang) OR (_ lang)) van hoe. hieu van nam luc ((va danh) or (va hanh)) va dau tren*.