Perhaps you should try some spelling variations:
dang thuoc » dung thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
tham thuc » nham thuc, pham thuc, tam thuc
thuc cach » truoc cach, thuc hanh, tuc cac
sach dang » sach dung, sach danh, sach nang
pho thong » he thong
cach hoa » cach hoan, cach hoc, bach hoa
tu sach » thu sach, su sach, te sach
nha pho » nha tho, nha khoa, nghe pho

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 tham thuc cach hoa hoc thuong ) or ( tu sach dang thuoc sach nha pho thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tham thuc cach hoa hoc thuong ) OR ( tu sach dang thuoc sach nha pho thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tham thuc cach hoa hoc thuong ) or ( tu sach dang thuoc sach nha pho thong ))*.