Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
te sach » toc sach
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
ve cac » va cac, vien cac
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua

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: te sach ((ky lang) OR (ky dang)) dai hoi. hieu ve cac duc van thanh ((di cua) OR (de cua)) vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky dang)) dai hoi. hieu ve cac duc van thanh ((di cua) OR (de cua)) vat~".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky dang)) dai hoi. hieu ve cac duc van thanh ((di cua) OR (de cua)) vat*.