Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
ban hanh » ban hang
mai khoi » mai khoa, tai khoa, dai khoa
nam thuc » nam thuoc, am thuc, nam thu
cac khoi » cac thoi, cac khoan, cach thoi
cam tuc » cam xuc, cam tu, dam thuc
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
sach 5 » sach y, sach 2
5 tang » 6 tang, 7 tang
vi cua » vai cua, di cua

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 5 tang ((mai khoi) OR (cac khoi)). hieu va ((cam tuc) or (nam thuc)) ban hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 5 tang ((mai khoi) OR (cac khoi)). hieu va ((cam tuc) OR (nam thuc)) ban hanh vi cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 5 tang ((mai khoi) OR (cac khoi)). hieu va ((cam tuc) or (nam thuc)) ban hanh vi cua viet*".