Perhaps you should try some spelling variations:
khau thong » khau thuong, khap thong, khau tong
khoan khau » khoanh khac, khoa kham, khoa phau
sach truc » cach thuc, sach tren, sach thu
truc thuc » truc thuoc, thuc thuc, truc thuy
cao khoan » cac khoan, tao khoang, lao khoa
sach tien » sach tren, sach thieu
tien thuc » trien thuc, kien thuc, bien thuc
thu thong » thuy thong, thu thang, thu tuong
thuc cao » thuoc cao, thuc co, thuc can
cao khoa » lao khoa, bao khoa, cac khoa
khoa thu » khoa than, hoai thu, ho thu
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 truc thuc cao khoan khau thong ) or ( su sach tien thuc cao khoa thu thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach truc thuc cao khoan khau thong ) OR ( su sach tien thuc cao khoa thu thong ))*.