Perhaps you should try some spelling variations:
sach tien » sach tren, sach thieu
sac dinh » xac dinh, cac dinh, sach kinh
tinh cao » tinh lao, tinh chat, tinh cach
cao khoa » lao khoa, bao khoa, cac khoa
khoa hoc » hoa hoc
sac tinh » dac tinh, cac tinh, sat tinh
dinh lam » dinh van, tinh lao
kha hoc » nha hoc, kha hoa, khi hoc
tien dy » tien do, tien ky, trien du
so sach » so sanh, bo sach, co sach
dy khoa » da khoa, ly khoa, y khoa
lam kha » lam khac, lam ha, lam cha
te sac » te sach, te cac, te san
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( tu sac tinh cao khoa hoc ) or ( te sac dinh lam kha hoc ))) or ( so sach tien dy khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( tu sac tinh cao khoa hoc ) OR ( te sac dinh lam kha hoc ))) OR ( so sach tien dy khoa hoc )).
• Adding a wildcard symbol may retrieve word variants: (((( tu sac tinh cao khoa hoc ) or ( te sac dinh lam kha hoc ))) or ( so sach tien dy khoa hoc ))*.