Perhaps you should try some spelling variations:
tren thuoc » trien thuoc, tren thuc, trung thuoc
khau thong » khau thuong, khap thong, khau tong
sach tren » sach tien, sach tranh
thuoc anh » thuoc thanh, thuoc dang, thuoc sach
cach thuc » anh thuc, cac thu
thuc thuc » hoc thuc
khoa khau » khoa kham, khoa phau, khoa chau
anh khoa » doanh khoa, hang khoa
thu cach » thuc cach, thu canh, tu cach
thuc anh » thuc hanh, thuy anh, thu anh
su sach » so sach, vu sach
khoa he » hoa he, khoa hoc, khong he

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach tren thuoc anh khoa he thong ) or ( thu cach thuc thuc anh khoa khau thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach tren thuoc anh khoa he thong ) OR ( thu cach thuc thuc anh khoa khau thong )).
• Adding a wildcard symbol may retrieve word variants: (( su sach tren thuoc anh khoa he thong ) or ( thu cach thuc thuc anh khoa khau thong ))*.