Perhaps you should try some spelling variations:
thien van » thi van
cham tuc » nham thuc, pham thuc, tham thuc
van hanh » van thanh, ban hanh, van anh
cau tren » cu tren, dau tren, ca tren
co sach » bo sach, cuon sach, hoc sach
va hanh » va thanh, va danh, ban hanh
y nang » ky nang, ly nang, v nang
va cau » van cau, va cac, va dau
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach y nang x hoi. ((lieu va) or (thien van)) cham tuc ((va hanh) OR (van hanh)) va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach y nang x hoi. ((lieu va) OR (thien van)) cham tuc ((va hanh) OR (van hanh)) va cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach y nang x hoi. ((lieu va) or (thien van)) cham tuc ((va hanh) OR (van hanh)) va cau tren".
• Adding a wildcard symbol may retrieve word variants: co sach y nang x hoi. ((lieu va) or (thien van)) cham tuc ((va hanh) OR (van hanh)) va cau tren*.