Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
sach ty » sach y, sach tu, sach thu
thuc va » thuc vat, thuc dan, thuc day
truc va » thuc vat, trung va
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sai ky » sac ky
vai su » va su, van su, lai su
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau ((truc va) OR (thuc va)) hanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sai ky)) nang xa hoi. hieu va cau ((truc va) OR (thuc va)) hanh vai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau ((truc va) OR (thuc va)) hanh vai su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau ((truc va) OR (thuc va)) hanh vai su triet*.