Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
hanh tai » thanh tai, hang tai, han tai
hanh dai » hanh dao, vanh dai, thanh dat
cac dac » cac dan, cac dai, cac bac
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
van hoi » van hoa, van hoc, van hoe
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
dac va » duc va, day va, dat va
ve cac » va cac, vien cac

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: hoc nganh ((ky tang) OR (ky dang)) van hoi. hieu ve cac dac va ((hanh dai) OR (hanh tai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc nganh ((ky tang) or (ky dang)) van hoi. hieu ve cac dac va ((hanh dai) OR (hanh tai)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: hoc nganh ((ky tang) or (ky dang)) van hoi. hieu ve cac dac va ((hanh dai) OR (hanh tai)) cua tre*.