Perhaps you should try some spelling variations:
hoc chuyen » khong chuyen
than thong » than thuong, toan thong, tran thong
sach song » sach dung
thuc cach » thuoc sach, truoc cach, thuc hanh
cach khoa » bach khoa, cac khoa, cac khoan
khoa than » khoa luan, hoa thai, hoa tan
thong may » thong xay, thong mang, thong va
song hoc » dong hoc, song ho, song hong
su sach » so sach, vu sach
tinh » dinh, kinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach song hoc chuyen đe ky thuat: kien thuc cach khoa than thong may ((tinh OR minh) or trinh)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach song hoc chuyen đe ky thuat: kien thuc cach khoa than thong may ((tinh OR minh) OR trinh).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach song hoc chuyen đe ky thuat: kien thuc cach khoa than thong may ((tinh OR minh) or trinh)".
• Adding a wildcard symbol may retrieve word variants: su sach song hoc chuyen đe ky thuat: kien thuc cach khoa than thong may ((tinh OR minh) or trinh)*.