Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
vu khach » vu khanh, vu khac, vay khach
hanh hoi » hanh thoi, hanh noi, hanh hoa
dang tay » dang xay, dung tay, dan tay
van hanh » van thanh, ban hanh, van anh
hoi cua » hoi chuc
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
qua cac » cua cac
vu sach » vu bach, su sach
dao tay » dao tao, dan tay

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) or (vu khach)) y ((dang tay) or (dao tay)) hoi. hieu qua cac duc van hanh hoi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) y ((dang tay) OR (dao tay)) hoi. hieu qua cac duc van hanh hoi cua viet.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) y ((dang tay) or (dao tay)) hoi. hieu qua cac duc van hanh hoi cua viet*.