Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang mai » nang ma, nang tai, lang mai
hanh vai » hanh vi, hanh va, hanh tai
co sach » cuon sach, hoc sach
bo sach » hoc sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
cac toi » cac thoi
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
toi va » thoi va, tuoi va, hoi va
vai su » va su, van su, lai su

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (((bo sach) OR (co sach)))) y nang mai hoi. hieu ve cac toi va hanh vai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (((bo sach) OR (co sach)))) y nang mai hoi. hieu ve cac toi va hanh vai su triet~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (((bo sach) OR (co sach)))) y nang mai hoi. hieu ve cac toi va hanh vai su triet*.