Perhaps you should try some spelling variations:
lam ngoc » pham ngoc, lam nguoi, lang ngoc
van hanh » van thanh, ban hanh, van anh
co sach » bo sach, cuon sach, hoc sach
ky dang » ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
lam loc » lam duoc
vi cua » vai cua, di cua
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: co sach ((ky dang) OR (ky nang)) xay hoi. hieu va ((lam loc) or (lam ngoc)) van hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((ky dang) OR (ky nang)) xay hoi. hieu va ((lam loc) OR (lam ngoc)) van hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((ky dang) OR (ky nang)) xay hoi. hieu va ((lam loc) or (lam ngoc)) van hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: co sach ((ky dang) OR (ky nang)) xay hoi. hieu va ((lam loc) or (lam ngoc)) van hanh vi cua te*.