Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
ban hanh » ban hang
thuc ban » thuoc ban, thuc dan, thu ban
hanh ve » hanh vi, hanh va, hanh kem
van chu » van chi, van phu, van cau
van cuu » van cau, van cu, van cua
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y ((nang ma) or (tang ma)) hoi. thien ((van cuu) OR (van chu)) thuc ban hanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y ((nang ma) OR (tang ma)) hoi. thien ((van cuu) OR (van chu)) thuc ban hanh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach y ((nang ma) or (tang ma)) hoi. thien ((van cuu) OR (van chu)) thuc ban hanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach y ((nang ma) or (tang ma)) hoi. thien ((van cuu) OR (van chu)) thuc ban hanh ve cua tre*.