Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cao truc » cau truc, vao truc, cao thuoc
va doanh » van doanh, vay doanh, va danh
tai quan » tai quang, hai quan, mai quan
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
truc va » thuc va, thuc vat, trung va
quan su » quan cua
va cao » va cac, va co, va dao

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 lang) OR (ky dang)) xa hoi. lieu va cao truc va doanh tai quan su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((ky lang) OR (ky dang)) xa hoi. lieu va cao truc va doanh tai quan su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ((ky lang) OR (ky dang)) xa hoi. lieu va cao truc va doanh tai quan su".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ((ky lang) OR (ky dang)) xa hoi. lieu va cao truc va doanh tai quan su*.