Perhaps you should try some spelling variations:
tien thuoc » trien thuoc, tin thuoc, bien thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
thuoc cach » thuc cach, truoc cach, cuoc cach
phap thong » phap phong, phap chong, phap tieng
sach tien » sach tren, sach thieu
sach khoa » bach khoa, sach nha, anh khoa
pho thong » he thong
bai thuoc » ban thuoc, bai hoc, cay thuoc
cach thoi » cac thoi, cach thuc, cach noi
thoi phap » thi phap, thuoc phap, hoi nhap
khoa pho » khoa phu, khoa khoa, khoa phau
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 tien thuoc sach khoa pho thong ) or ( tu cac bai thuoc cach thoi phap thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tien thuoc sach khoa pho thong ) OR ( tu cac bai thuoc cach thoi phap thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tien thuoc sach khoa pho thong ) or ( tu cac bai thuoc cach thoi phap thong ))*.