Perhaps you should try some spelling variations:
sach tren » sach tien, sach tranh
thuc bach » truc bach, thuc cach, thuoc sach
bach khoa » anh khoa
khoa than » khoa luan, hoa thai, hoa tan
than cong » thanh cong, thuan cong, phan cong
so sach » so sanh, bo sach, co sach
cong ha » cong hoa, dong ha, cong tac
ha dinh » ha tinh, va dinh, ba dinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tren ((hoc chuyen) OR (khong chuyen)) đe ky thuat: kien thuc bach khoa than cong ha dinh~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tren ((hoc chuyen) OR (khong chuyen)) đe ky thuat: kien thuc bach khoa than cong ha dinh".
• Adding a wildcard symbol may retrieve word variants: so sach tren ((hoc chuyen) OR (khong chuyen)) đe ky thuat: kien thuc bach khoa than cong ha dinh*.