Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cac truc » cau truc, cac tru, cac trung
cuu tre » cua tre, cau treo
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
ve cac » va cac, vien cac

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 ky ((mang xa) or (lang xa)) hoi. hieu ve cac truc va hanh vi ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang xa) OR (lang xa)) hoi. hieu ve cac truc va hanh vi ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((mang xa) or (lang xa)) hoi. hieu ve cac truc va hanh vi ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang xa) or (lang xa)) hoi. hieu ve cac truc va hanh vi ((cuu tre) OR (cau tren))*.