Perhaps you should try some spelling variations:
tranh thuc » trinh thuc, trang thuc, thanh thuy
khoa thong » hoa thong, thoai thong, pho thong
khan thong » khap thong, khau thong, nhan thong
hanh sinh » hanh tinh, hanh dinh, hinh sinh
sinh khoa » sinh hoc, sinh hoat, anh khoa
sach tri » sach tai, sach tren, sach truc
tue cach » tu cach, thuc cach, ve cach
cach kho » bach khoa, cach thoi, cach pha
kho khan » khoa kham, khoa than
te canh » ve canh, te danh, re canh
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te canh tranh thuc hanh sinh khoa thong ) or ( tu sach tri tue cach kho khan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te canh tranh thuc hanh sinh khoa thong ) OR ( tu sach tri tue cach kho khan thong )).
• Adding a wildcard symbol may retrieve word variants: (( te canh tranh thuc hanh sinh khoa thong ) or ( tu sach tri tue cach kho khan thong ))*.