Perhaps you should try some spelling variations:
dung khoa » dung cho
hieu van » hieu va, thien van, lieu va
cac thuc » cach thuc, cac thu, can thuc
doc sach » hoc sach, toc sach, nuoc sach
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
khoa hoc » hoa hoc
cua cay » cua cac
te sach » toc sach
van cac » van hac, van cau, van bac
ty dung » tay dung, ly dung, te dung
cua chu » sua chua

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) OR (doc sach)) ty dung khoa hoc. hieu van cac thuc dan hanh vi ((cua cay) OR (cua chu))~.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ty dung khoa hoc. hieu van cac thuc dan hanh vi ((cua cay) or (cua chu))*.