Perhaps you should try some spelling variations:
bai phoi » bai choi, bai hoc, dai hoi
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, hoa viet, cua vat
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
ky va » ke va, my va, ky la
hien » bien, tien, dien

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ((ky va) OR (ly va)) bai phoi. hieu ((vien dai) or (hien dai)) thuc va hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ((ky va) OR (ly va)) bai phoi. hieu ((vien dai) OR (hien dai)) thuc va hanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ((ky va) OR (ly va)) bai phoi. hieu ((vien dai) or (hien dai)) thuc va hanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu cac ((ky va) OR (ly va)) bai phoi. hieu ((vien dai) or (hien dai)) thuc va hanh vai cua viet*.