Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
tham tuc » tham thuc, thai tuc, nham thuc
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, dia danh, va thanh
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
va dan » ca dan, va dao, va dau
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. hieu van tham tuc ((((va danh) OR (va hanh))) or (va dan)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu van tham tuc ((((va danh) OR (va hanh))) OR (va dan)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu van tham tuc ((((va danh) OR (va hanh))) or (va dan)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu van tham tuc ((((va danh) OR (va hanh))) or (va dan)) di cua tre*.