Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
hanh lai » hanh lam, thanh lap, thanh loi
vuc nang » cuc nang, vu nang, chuc nang
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
qua cau » quan cau, qua cac, qua ca
ca viet » va viet, co viet, hoa viet
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang

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 lai) OR (hanh tai)) 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 lai) OR (hanh tai)) 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 lai) OR (hanh tai)) 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 lai) OR (hanh tai)) ca viet*.