Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
du va » dau va, tu va, su va

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) OR (toc sach)) ky nang xa hoi. hieu va cac du va danh va su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang xa hoi. hieu va cac du va danh va su triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang xa hoi. hieu va cac du va danh va su triet*.