Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van ban
vuc nang » cuc nang, vu nang, chuc nang
qua cau » quan cau, qua cac, qua ca
van anh » van thanh, tuan anh, van minh
su sach » so sach, vu sach
ca viet » va viet, co viet, hoa viet
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang
va ca » va cac, va cao, va cai

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 ((v nang) or (vuc nang)) ma hoi. hieu qua cau truc ((van hanh) OR (van anh)) va ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (vuc nang)) ma hoi. hieu qua cau truc ((van hanh) OR (van anh)) va ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) or (vuc nang)) ma hoi. hieu qua cau truc ((van hanh) OR (van anh)) va ca viet".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (vuc nang)) ma hoi. hieu qua cau truc ((van hanh) OR (van anh)) va ca viet*.