Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh doi » thanh doi, hanh noi, hang doi
va hanh » van hanh, va thanh, va danh
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
doi cua » dai cua, hoi cua
vu sach » vu bach, su sach, vu khach

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((nang ma) OR (sang ma)) hoi. hieu qua ((nhan luc) OR (nang luc)) va hanh doi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((nang ma) OR (sang ma)) hoi. hieu qua ((nhan luc) or (nang luc)) va hanh doi cua viet~".
• Adding a wildcard symbol may retrieve word variants: vu sach y ((nang ma) OR (sang ma)) hoi. hieu qua ((nhan luc) or (nang luc)) va hanh doi cua viet*.