Perhaps you should try some spelling variations:
phau thong » phap thong, khau thong, phan thong
khan thong » khap thong, khau thong, nhan thong
sach tien » sach tren, sach thieu
tien thuc » trien thuc, kien thuc, bien thuc
khoa phau » hoa phan, khoa kham, khoa than
thuc cac » thuc cach, tuc cac, phuc cac
kho khan » khoa kham, khoa than
thu sach » tu sach, thuat sach, thuoc sach
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
cac khoa » cac khoan, cac khoi, dac khoa
te sach » toc sach
cac kho » cac khoi, cac khu, cac ho

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

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