Perhaps you should try some spelling variations:
thieu nang » thieu khang, thieu quang, thi nang
thien nang » thien bang, thien dang, trien nang
toc sach » hoc sach, doc sach, thuoc sach
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu va, hieu van
anh vi » hanh vi, anh ve, anh vu
anh va » hanh va
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((thieu nang) or (thien nang)) co hoc. hieu ve cac vuc van ((anh vi) OR (anh va)) cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((thieu nang) OR (thien nang)) co hoc. hieu ve cac vuc van ((anh vi) OR (anh va)) cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((thieu nang) or (thien nang)) co hoc. hieu ve cac vuc van ((anh vi) OR (anh va)) cua cau*".