Perhaps you should try some spelling variations:
cau thuc » cau truc, can thuc, cau phuc
cuu thuc » cuu tac
van hanh » van thanh, ban hanh, van anh
cau tren » cu tren, dau tren, ca tren
vu sach » vu bach, su sach, vu khach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
vi cau » va cau, ve cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach y ((nang xa) or (lang xa)) hoi. lieu va ((cau thuc) OR (cuu thuc)) van hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((nang xa) OR (lang xa)) hoi. lieu va ((cau thuc) OR (cuu thuc)) van hanh vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((nang xa) or (lang xa)) hoi. lieu va ((cau thuc) OR (cuu thuc)) van hanh vi cau tren".
• Adding a wildcard symbol may retrieve word variants: vu sach y ((nang xa) or (lang xa)) hoi. lieu va ((cau thuc) OR (cuu thuc)) van hanh vi cau tren*.