Perhaps you should try some spelling variations:
nang viet » anh viet
doc sach » hoc sach, toc sach, nuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
thuc day » thuc vat
viet cua » viec cua, viet ca, viet qua
nang xa » nang x, lang xa, nang ma
va nham » va cham, va tham, va nha
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach v nang xa hoi. lieu va nham ((thuc dan) or (thuc day)) nang viet cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach v nang xa hoi. lieu va nham ((thuc dan) OR (thuc day)) nang viet cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sach v nang xa hoi. lieu va nham ((thuc dan) or (thuc day)) nang viet cua tre*.