Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dung
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
ve cau » ke cau, va cau, le cau
ve cac » va cac, vien cac
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((van nang) OR (van dong)) x hoi. hieu ((ve cau) or (ve cac)) thuc dan hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((van nang) OR (van dong)) x hoi. hieu ((ve cau) OR (ve cac)) thuc dan hanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((van nang) OR (van dong)) x hoi. hieu ((ve cau) or (ve cac)) thuc dan hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((van nang) OR (van dong)) x hoi. hieu ((ve cau) or (ve cac)) thuc dan hanh de cua tre*.