Perhaps you should try some spelling variations:
khan thong » khap thong, khau thong, nhan thong
hanh trinh » canh tranh, hanh chinh
trinh thi » trinh tai, dinh thi, trinh tu
cac khoa » cac khoan, cac khoi, dac khoa
khoa hoc » hoa hoc
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
thuc dan » thuc hanh, hoc dan, thuc vat
pho khan » kho khan, pho phan, phi khanh
su hanh » su thanh, du hanh, lu hanh
thi cac » thi cuc, tai cac, thi tac
tu sach » thu sach, su sach, te sach
dan pho » dan tho, luan pho

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su hanh trinh thi cac khoa hoc thuong ) or ( tu sach tri thuc dan pho khan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su hanh trinh thi cac khoa hoc thuong ) OR ( tu sach tri thuc dan pho khan thong )).
• Adding a wildcard symbol may retrieve word variants: (( su hanh trinh thi cac khoa hoc thuong ) or ( tu sach tri thuc dan pho khan thong ))*.