Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
cac toi » cac thoi
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
bo sach » co sach, hoc sach
mai hoi » mai khoi, dai hoi, lai hoi
ve cac » va cac, vien cac
y nang » ky nang, v nang, may nang
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)) ((y nang) OR (ly 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)) ((y nang) OR (ly 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)) ((y nang) OR (ly nang)) mai hoi. hieu ve cac toi va hanh vai su triet*.