Perhaps you should try some spelling variations:
sach trien » sach tren, sach thieu, cach thien
khau thong » khau thuong, khap thong, khau tong
trien thuc » trien thuoc, tren thuc, trien thuat
cach khong » cach phong, cac phong, bach khang
sach tien » sach tren, sach thieu
tien thuc » kien thuc, bien thuc, tien thu
khoa khau » khoa kham, khoa phau, khoa chau
thuc cach » thuoc sach, truoc cach, thuc hanh
thuc cac » tuc cac, phuc cac, thac cac
cac khoa » cac khoan, cac khoi, dac khoa
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach

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 tien thuc cac khoa khau thong ) or ( su sach trien thuc cach khong _ thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tien thuc cac khoa khau thong ) OR ( su sach trien thuc cach khong _ thong ))*.