Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
hieu van » hieu va, thien van, lieu va
van nham » van nam, van nhan, van tham
cau tren » cu tren, dau tren, ca tren
co sach » bo sach, cuon sach, hoc sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
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 ky nang x hoi. hieu van nham thuc ((va hanh) OR (va danh)) va cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ky nang x hoi. hieu van nham thuc ((va hanh) OR (va danh)) va cau tren".
• Adding a wildcard symbol may retrieve word variants: co sach ky nang x hoi. hieu van nham thuc ((va hanh) OR (va danh)) va cau tren*.