Perhaps you should try some spelling variations:
phap thong » phap phong, phap chong, pho thong
thuoc sach » hoc sach, nuoc sach, thuat sach
tac thuoc » tao thuoc, truc thuoc, tac thuong
sach khoa » bach khoa, sach nha, anh khoa
sach tham » sach nha
tham thuc » nham thuc, pham thuc, tam thuc
thuc sach » thu sach, thuc cach, thuat sach
khoa phap » khoa phau, khoan phai, khong phap
sanh tac » canh tac, sang tac, anh ta
so sanh » do sanh
khoa he » hoa he, khoa hoc, khong he
co sach » bo sach, cuon sach, hoc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh tac thuoc sach khoa he thong ) or ( co sach tham thuc sach khoa phap thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh tac thuoc sach khoa he thong ) OR ( co sach tham thuc sach khoa phap thong )).
• Adding a wildcard symbol may retrieve word variants: (( so sanh tac thuoc sach khoa he thong ) or ( co sach tham thuc sach khoa phap thong ))*.