Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
cua viet » ca viet, hoa viet, cua vat
dan hanh » dan khanh, dan thanh, ban hanh
mang mai » mang may, lang mai, mang lai
nam thuc » nam thuoc, am thuc, nam thu
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky mang » ky nang, ke mang, ky dang
co sach » bo sach, cuon sach, hoc sach
vi cua » vai cua, di cua
ve nam » he nam, va nam, le nam

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) or (co sach)) ky mang mai hoi. hieu ve nam thuc ((dan hanh) OR (dang hanh)) vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) ky mang mai hoi. hieu ve nam thuc ((dan hanh) OR (dang hanh)) vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) ky mang mai hoi. hieu ve nam thuc ((dan hanh) OR (dang hanh)) vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) ky mang mai hoi. hieu ve nam thuc ((dan hanh) OR (dang hanh)) vi cua viet*.