Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
nghe thong » he thong
sach ngan » sach ngon, sach nha, sach han
ngan cong » nganh cong, nganh nong, ngan hang
trinh han » trinh quan
dinh van » sinh vat
tinh va » tich va, trinh van, trinh vat

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ngan cong nghe thong ((tinh va) OR (((dinh van) OR (trinh han)))) truyen thong~.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ngan cong nghe thong ((tinh va) or (((dinh van) or (trinh han)))) truyen thong*.