Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
tu cach » tu cac
hanh di » hanh vi, hanh de, hang di
xuc van » duc van, luc van, xuc ban
cac xuc » cam xuc, cac nuoc, chat xuc
sang ma » tang ma, nang ma, sang tao
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thu sach)) ky ((sang ma) or (nang cao)) hoi. hieu vien cac xuc van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thu sach)) ky ((sang ma) OR (nang cao)) hoi. hieu vien cac xuc van hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thu sach)) ky ((sang ma) or (nang cao)) hoi. hieu vien cac xuc van hanh di cua tre*.