Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan
dau treo » dau tren, cau treo, dau theo
hanh va » hang va, hanh vi
tu sac » tu sach, tu san, tu bac
nang o » nang co, nang ho, nang ro
va nam » van nam, ha nam, va nay
va dau » va dao
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu cac)) ky nang o hai. lieu va nam ((thuc dan) OR (thuc vat)) hanh va dau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu cac)) ky nang o hai. lieu va nam ((thuc dan) OR (thuc vat)) hanh va dau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) or (tu cac)) ky nang o hai. lieu va nam ((thuc dan) OR (thuc vat)) hanh va dau treo".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu cac)) ky nang o hai. lieu va nam ((thuc dan) OR (thuc vat)) hanh va dau treo*.