Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
canh tac » canh tay, canh giac, cong tac
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
thai cua » than cua, tai cuc, tri cua
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky canh » ky anh, ky cach, ky danh
tac hoi » tao hoi, tay hoi, tac hai
cac thu » cach thuc, cac thoi
thu van » thuc van, thuy van, tu van
vai cua » dai cua, hai cua, lai 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 ky canh tac hoi. hieu vien cac thu van hanh ((vai cua) or (thai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky canh tac hoi. hieu vien cac thu van hanh ((vai cua) OR (thai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky canh tac hoi. hieu vien cac thu van hanh ((vai cua) or (thai cua)) triet*.