Perhaps you should try some spelling variations:
sanh trinh » hanh trinh, anh trinh, sinh trinh
trinh thuc » trinh tu, trinh thi
khoan nhoi » khoan hoi, khoa hoi, khoa noi
nhoi trong » nuoi trong, choi trong, hoi trong
thuc hang » thuc hanh, thu hang, phuc hang
hang khoa » dung khoa
pho thong » he thong
khoa pho » khoa phu, khoa khoa, khoa phau
sanh tai » sang tai, hanh tai, anh tai
tai thuc » thai thuc, tri thuc, dai thuc
thuc cac » thuc cach, tuc cac, phuc cac
so sanh » do sanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh trinh thuc hang khoa pho thong ) or ( so sanh tai thuc cac khoan nhoi trong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh trinh thuc hang khoa pho thong ) OR ( so sanh tai thuc cac khoan nhoi trong )).
• Adding a wildcard symbol may retrieve word variants: (( so sanh trinh thuc hang khoa pho thong ) or ( so sanh tai thuc cac khoan nhoi trong ))*.