Perhaps you should try some spelling variations:
mai khoi » mai khoa, cac khoi, dai khoa
hang tai » hang va
tai khoa » da khoa, noi khoa
te sach » toc sach
luu van » cuu van, luan van, luu hanh
cuu tre » cua tre, cau tren, cau treo
tam luu » ta luu, tam buu
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
ve tam » ve tac, ve tai, va tam

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky lang ((mai khoi) or (tai khoa)). hieu ve tam luu van ((hang tai) OR (dung tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky lang ((mai khoi) OR (tai khoa)). hieu ve tam luu van ((hang tai) OR (dung tai)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky lang ((mai khoi) or (tai khoa)). hieu ve tam luu van ((hang tai) OR (dung tai)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky lang ((mai khoi) or (tai khoa)). hieu ve tam luu van ((hang tai) OR (dung tai)) cuu tre*.