Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau treo » cau theo, cau triet, cau trieu
gia hanh » gia thanh, giao hanh, gia anh
cac duc » cao duc, cac dac, cac nuoc
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
ky lang » ky nang, ky dang, ky tang

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