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
nam thuc » nam thuoc, am thuc, nam thu
mang mai » mang may, lang mai, mang lai
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
ky mang » ky nang, ke mang, ky dang
bo sach » co sach, hoc sach
hieu ve » hieu va, hieu van
ve nam » he nam, va nam, le nam
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) or (bo 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 (bo 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 (bo sach)) ky mang mai hoi. hieu ve nam thuc ((dan hanh) or (dang hanh)) vi cua viet*.