Perhaps you should try some spelling variations:
tren thuat » trien thuat, trong thuat, thien thuat
thuat bach » thuat sach, thuat mach, thuat tach
bach khoan » bach khoa, cac khoan, bach hoa
khoan phai » khong phai, khoa phau, khoan hoi
phai thong » phap thong, phai tuong, phan thong
thuc hang » thuc hanh, thu hang, phuc hang
hang khoa » dung khoa
sach tren » sach tien, sach tranh
sach tri » sach tai, sach truc, sach bai
tri thuc » tri tue
vu sach » vu bach, su sach, vu khach
khoa he » hoa he, khoa hoc, khong he
so sach » so sanh, bo sach, co sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu sach tri thuc hang khoa he thong ) or ( so sach tren thuat bach khoan phai thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach tri thuc hang khoa he thong ) OR ( so sach tren thuat bach khoan phai thong )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach tri thuc hang khoa he thong ) or ( so sach tren thuat bach khoan phai thong ))*.