Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » thuat sach, thuoc sach, thu hoach
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
thai cua » than cua, tri cua, dai cua
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
ma hoi » mai hoi, xa hoi, ma hoa

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: ((tu sach) OR (thu sach)) ky nang ma hoi. hieu vien cac luc van hanh ((thai cua) OR (tai cuc)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang ma hoi. hieu vien cac luc van hanh ((thai cua) OR (tai cuc)) tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang ma hoi. hieu vien cac luc van hanh ((thai cua) OR (tai cuc)) tre*.