Perhaps you should try some spelling variations:
thien van » thi van
cuon sach » duong sach, cuoc cach, nuoc sach
cham tuc » nham thuc, pham thuc, tham thuc
hieu van » hieu va, lieu va, hieu ve
co sach » bo sach, hoc sach
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cu tren » tu tren, dua tren
tuc va » thuc va, truc va, tuc xa
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho
va cu » va cau, va chu, va su

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