Perhaps you should try some spelling variations:
sach kem » hanh kem
cham cuu » cap cuu, chat cua
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
su tien » su kien, su hien, tu tieng
nang ma » tang ma, sang ma, nang cao
cuu va » cuu van, cuu ve
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach kem) or (sach y)) ((nang ma) or (nang x)) hoi. hieu va cham cuu va hanh vi su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach kem) OR (sach y)) ((nang ma) OR (nang x)) hoi. hieu va cham cuu va hanh vi su tien.
• Adding a wildcard symbol may retrieve word variants: su ((sach kem) or (sach y)) ((nang ma) or (nang x)) hoi. hieu va cham cuu va hanh vi su tien*.