Perhaps you should try some spelling variations:
hanh doi » thanh doi, hanh noi, hang doi
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
van lam » van nam
van cam » van nam, van cau, van dam
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
su viet » so viet
doi su » oi su, don su, voi su

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 ((nang xa) or (lang xa)) hoi. hieu ((van cam) OR (van lam)) thuc va hanh doi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang xa)) hoi. hieu ((van cam) OR (van lam)) thuc va hanh doi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (lang xa)) hoi. hieu ((van cam) OR (van lam)) thuc va hanh doi su viet*".