Perhaps you should try some spelling variations:
trien phuong » trinh phuong, tran phuong, thi phuong
hoach trien » hoach chien
thuoc sach » hoc sach, nuoc sach, thuat sach
khan thong » khap thong, khau thong, nhan thong
phuong bac » phuong cach, phuong tay, phuong mai
khoa thong » hoa thong, thoai thong, pho thong
thu thuoc » tu thuoc, thu thuc, tru thuoc
khoa khoa » hoa khoa, khuan khoa, khoa hoc
sach kho » bach khoa, sach dao, sach nha
kho khan » khoa kham, khoa than
bac khoa » bach khoa, dac khoa, ba khoa
cac thu » cach thuc, cac thoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu cac thu thuoc sach kho khan thong ) or ( thu hoach trien phuong bac khoa khoa thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu cac thu thuoc sach kho khan thong ) OR ( thu hoach trien phuong bac khoa khoa thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu cac thu thuoc sach kho khan thong ) or ( thu hoach trien phuong bac khoa khoa thong ))*.