Perhaps you should try some spelling variations:
thieu tuong » hieu tuong, bieu tuong, thu tuong
hoc trong » hoc thuong, hoc tieng, dot trong
sach tren » sach tien, sach tranh
tren thuc » trien thuc, tron thuc, trinh thuc
thuc bach » truc bach, thuc cach, thuoc sach
tuong ho » tong hop
khoa hoc » hoa hoc
toc sach » hoc sach, doc sach, thuoc sach
tu thong » tu thuong, tu tuong, tu trong
tu sach » thu sach, su sach, te sach
ho khoa » hoc khoa, hoi khoa, hop khoa
mai tu » tai tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach thieu tuong ho khoa hoc trong ) or ( toc sach tren thuc bach mai tu thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach thieu tuong ho khoa hoc trong ) OR ( toc sach tren thuc bach mai tu thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach thieu tuong ho khoa hoc trong ) or ( toc sach tren thuc bach mai tu thong ))*.