Perhaps you should try some spelling variations:
hien sach » dien sach, kien sach, thien hach
canh sinh » canh tinh, canh binh, tinh sinh
dung cong » dung trong
vat dung » van dung, va dung, viet dung
dan than » dan chan, van than, dan toan
ban than » ban thanh, van thanh, ban hang
van tan » van tuan, van ban, van tai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien sach - canh sinh vat dung cong ((van tan) OR (((dan than) OR (ban than)))) tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien sach - canh sinh vat dung cong ((van tan) or (((dan than) OR (ban than)))) tap~".
• Adding a wildcard symbol may retrieve word variants: hoc hien sach - canh sinh vat dung cong ((van tan) or (((dan than) OR (ban than)))) tap*.