Perhaps you should try some spelling variations:
phai thong » phap thong, phai tuong, phan thong
khoan phai » khong phai, khoa phau, khoan hoi
thuc dung » thuoc dung, thuy dung, tuc dung
hoc thong » hoc thuong, hoc trong, hoc hong
sach tham » sach nha
tham thuc » nham thuc, pham thuc, tam thuc
dan khoan » dan khoa, dai khoang, toan khoan
dung hoa » dung khoa, duong hoa, dung hoai
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
sach am » sach dao, sach bai, sach cap

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 am thuc dung hoa hoc thong ) or ( tu sach tham thuc dan khoan phai thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach am thuc dung hoa hoc thong ) OR ( tu sach tham thuc dan khoan phai thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach am thuc dung hoa hoc thong ) or ( tu sach tham thuc dan khoan phai thong ))*.