Perhaps you should try some spelling variations:
khoan pho » khoan nhoi, khoan phai, khoan hoi
pho thong » he thong
khoa phan » hoa phan, khoa than, khoa phau
phan hong » phan cong, pham hong, phan song
sach bao » sach dao, sach bai, sach bac
bao thuc » cao thuoc, am thuc, va thuc
thuc cac » thuc cach, tuc cac, phuc cac
xa trong » xa truong, ca trong, va trong
cac khoa » cac khoi, dac khoa, cao khoa
su sach » so sach, vu sach
tu cach » tu cac
cach xa » sach xa, cac xa, cach ta

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach bao thuc cac khoan pho thong ) or ( tu cach xa trong cac khoa phan hong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach bao thuc cac khoan pho thong ) OR ( tu cach xa trong cac khoa phan hong )).
• Adding a wildcard symbol may retrieve word variants: (( su sach bao thuc cac khoan pho thong ) or ( tu cach xa trong cac khoa phan hong ))*.