Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
va hang » van hang, va nang, va hanh
tai cua » thai cua, tai cuc, tri cua
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
nam tuc » nam thuc, nam truc, nam tu
va lang » va nang, hoa lang
va nam » van nam, ha nam, va nay
cua te » cua tu

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