Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
van cau » van dau, van hau, van chat
vai cua » dai cua, hai cua, lai cua
duc van » duc va, duc tan, duc manh
van lam » van nam
dang ma » dang mau, dang mam, dang mat
ty dang » ty xang, ky dang, ty hang
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ty dang ma hoa. hieu ((van lam) or (van cau)) duc van hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty dang ma hoa. hieu ((van lam) OR (van cau)) duc van hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty dang ma hoa. hieu ((van lam) or (van cau)) duc van hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty dang ma hoa. hieu ((van lam) or (van cau)) duc van hanh vai cua tre*.