Perhaps you should try some spelling variations:
tren thuoc » trien thuoc, tren thuc, trung thuoc
sach tren » sach tien, sach tranh
thuoc ban » thuoc tan, thuoc dang, thu ban
hoach thu » hoach thay, doanh thu, hoach su
dan khong » dai khong, dan phong, dao khong
ban khoa » san khoa, van khoa, ba khoa
khoa pho » khoa phu, khoa khoa, khoa phau
thu thuc » thuc thuc, thu thuoc, thue thuc
thuc dan » thuc hanh, hoc dan, thuc vat
khong he » khong khi, hong ha, khong _
tu sach » thu sach, su sach, te sach

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

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