Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
nang thuc » dang thuoc, nhanh thuc, trang thuc
dung cong » dung trong
nang dua » nang du, nang suat, nang quan
cong van » cong vang, cong san, song van
van tan » van tuan, van ban, van tai
tan ban » toan ban, tang ban, van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - anh ((nang dua) or (nang thuc)) dung cong van tan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - anh ((nang dua) OR (nang thuc)) dung cong van tan ban*.