Perhaps you should try some spelling variations:
cham cuu » cap cuu, chat cua
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va cham » va chat, va tham
thai va » thai van
tai va » mai va, tri va, dai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((nang xa) or (lang xa)) hoi. hieu va cham cuu van hanh ((tai va) or (thai va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang xa) OR (lang xa)) hoi. hieu va cham cuu van hanh ((tai va) OR (thai va)) thiet.
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) or (lang xa)) hoi. hieu va cham cuu van hanh ((tai va) or (thai va)) thiet*.