Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
tai khoa » da khoa, noi khoa
mai khoi » mai khoa, cac khoi, dai khoa
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau treo
ky lang » ky nang, ky dang, ky tang
ve cam » ve cham, ve cac, va cam

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: tu cac ky lang ((mai khoi) OR (tai khoa)). hieu ve cam thuc van hanh tai ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky lang ((mai khoi) OR (tai khoa)). hieu ve cam thuc van hanh tai ((cuu tre) or (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: tu cac ky lang ((mai khoi) OR (tai khoa)). hieu ve cam thuc van hanh tai ((cuu tre) or (cau tren))*.