Perhaps you should try some spelling variations:
kham thong » khap thong, khau thong, pham thuong
khoan kham » khoa kham, khoanh khac, khoan cam
sach tren » sach tien, sach tranh
tren thuc » trien thuc, tron thuc, trinh thuc
pho thong » he thong
sach thai » sach tham, sac thai, sach tai
thai thuc » thai thuy, thai tuc, tham thuc
thuc anh » thuc hanh, thuy anh, thu anh
anh khoa » doanh khoa, hang khoa
khoa pho » khoa phu, khoa khoa, khoa phau
thuc cac » thuc cach, tuc cac, phuc cac
te sach » toc sach
tu sach » thu sach, su sach, tu cach

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach tren thuc anh khoa pho thong ) OR ( tu sach thai thuc cac khoan kham thong ))~.
• Adding a wildcard symbol may retrieve word variants: (( te sach tren thuc anh khoa pho thong ) or ( tu sach thai thuc cac khoan kham thong ))*.