Perhaps you should try some spelling variations:
hoach tren » hoach trong, hoach toan, hoc tren
khoan khoa » khuan khoa, khoa khoa, toan khoa
khoa thong » hoa thong, thoai thong, pho thong
thoi thong » thoai thong, hoi thong, thong thong
tren thuc » trien thuc, tron thuc, trinh thuc
thuc cac » thuc cach, tuc cac, phuc cac
sach tri » sach tai, sach tren, sach truc
tue bach » truc bach, thi bach, vu bach
bach cua » bach qua, mach cua, cach cua
cua thoi » cua hoi, cua toi, cua khoi
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: (( thu hoach tren thuc cac khoan khoa thong ) or ( tu sach tri tue bach cua thoi thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu hoach tren thuc cac khoan khoa thong ) OR ( tu sach tri tue bach cua thoi thong )).
• Adding a wildcard symbol may retrieve word variants: (( thu hoach tren thuc cac khoan khoa thong ) or ( tu sach tri tue bach cua thoi thong ))*.