Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
sach thu » sach thue, sach thieu, sach tham
thuc van » thuc vat, thuc dan, thuc va
cu tren » tu tren, dua tren
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
va dao » ca dao
tai cu » tai cuc, tai cua, tai co

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 (sach thu)) nang xa hoi. lieu ((va dau) OR (va dao)) thuc van hanh tai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang xa hoi. lieu ((va dau) OR (va dao)) thuc van hanh tai cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach thu)) nang xa hoi. lieu ((va dau) OR (va dao)) thuc van hanh tai cu tren".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang xa hoi. lieu ((va dau) OR (va dao)) thuc van hanh tai cu tren*.