Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
manh khai » minh khai, dang khai, lanh hai
thuc dan » thuc hanh, hoc dan
manh hai » lanh hai, minh hai, thanh hai
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
va viet » hoa viet, san viet, mai viet
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky nang x ho. hieu ve nam ((thuc dan) or (thuc vat)) ((manh khai) OR (manh hai)) va viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang x ho. hieu ve nam ((thuc dan) OR (thuc vat)) ((manh khai) OR (manh hai)) va viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang x ho. hieu ve nam ((thuc dan) or (thuc vat)) ((manh khai) OR (manh hai)) va viet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang x ho. hieu ve nam ((thuc dan) or (thuc vat)) ((manh khai) OR (manh hai)) va viet*.