Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
va hanh » van hanh, va thanh, ban hanh
mang xa » lang xa, mang may, dang xay
va danh » va dinh, va dan, dia danh
hieu ve » hieu va, hieu van
cam luc » cam xuc, cau luc
ke cau » ket cau
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky ((mang xa) or (nang x)) hoi. hieu ve cam luc ((va hanh) OR (va danh)) ke cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((mang xa) OR (nang x)) hoi. hieu ve cam luc ((va hanh) OR (va danh)) ke cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky ((mang xa) or (nang x)) hoi. hieu ve cam luc ((va hanh) OR (va danh)) ke cau tren*".