Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
ky lang » ky nang, ky dang, ky tang
hanh ky » hanh kem
hanh ke » hanh kem, thanh ke, hanh ve
bach ky » bac ky
cao loc » cao hoc, cao oc, chon loc
lang xa » lang ha, dang xay, lang van
cao toc » cac toc, cao hoc, cao thuoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky lang xa hoi. hieu qua ((cao loc) or (cao toc)) ban ((hanh ke) OR (hanh ky)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky lang xa hoi. hieu qua ((cao loc) OR (cao toc)) ban ((hanh ke) OR (hanh ky)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky lang xa hoi. hieu qua ((cao loc) or (cao toc)) ban ((hanh ke) OR (hanh ky)) cau tren".
• Adding a wildcard symbol may retrieve word variants: vu bach ky lang xa hoi. hieu qua ((cao loc) or (cao toc)) ban ((hanh ke) OR (hanh ky)) cau tren*.