Perhaps you should try some spelling variations:
khan thong » khap thong, khau thong, nhan thong
sach tren » sach tien, sach tranh
tren thuc » trien thuc, tron thuc, trinh thuc
phu thong » pho thong, phap thong, khau thong
hanh kho » hanh khu, hang khoa, hanh theo
kho khan » khoa kham, khoa than
sach tri » sach tai, sach truc, sach bai
te sach » toc sach
vu sach » vu bach, su sach, vu khach
tri phu » thi phu, tri thuc, tri phan
phu cac » phuc cac, pha cac, phu can
cac hoa » cac hoat, cac khoa, cau hoa
hoa phu » khoa phu, hoa phi, hoi phu

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 tren thuc hanh kho khan thong ) or ( vu sach tri phu cac hoa phu thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach tren thuc hanh kho khan thong ) OR ( vu sach tri phu cac hoa phu thong )).
• Adding a wildcard symbol may retrieve word variants: (( te sach tren thuc hanh kho khan thong ) or ( vu sach tri phu cac hoa phu thong ))*.