Perhaps you should try some spelling variations:
phan thong » phan thuong, phan hong, phan tong
cach khong » cach phong, cac phong, bach khang
hang khoa » dung khoa
khoa phan » hoa phan, khoa than, khoa phau
sach tron » sach tren, sach tranh, sanh trong
tron thuc » trong thuc, toan thuc, trong thu
thuc cach » thuoc sach, truoc cach, thuc hanh
xac thai » rac thai, sac thai, xa thai
thai hoc » dai hoc, bai hoc, hoi hoc
hoc hang » hoc hanh, hoc bang, hoc tang
khong he » khong khi, hong ha, khong _
tu sach » thu sach, su sach, te sach
su xac » pu xac, su cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su xac thai hoc hang khoa phan thong ) or ( tu sach tron thuc cach khong he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su xac thai hoc hang khoa phan thong ) OR ( tu sach tron thuc cach khong he thong )).
• Adding a wildcard symbol may retrieve word variants: (( su xac thai hoc hang khoa phan thong ) or ( tu sach tron thuc cach khong he thong ))*.