Perhaps you should try some spelling variations:
cachh khoan » cac khoan, cach hoan
sach trien » sach tien, sach tren, sach thieu
trien thuc » trien thuoc, tren thuc, trien thuat
cach khoin » cac khoan, cach thoi, cac khoi
manh trong » manh truong, anh trong, manh trung
trong thuc » trong thu, thuong thuc, trong thuat
khoan nhoi » khoan hoi, khoa hoi, khoa noi
thuc cach » thuoc sach, truoc cach, thuc hanh
khoin pho » khoi tho
pho thong » he thong
nhoi tong » noi tong, nuoi trong, choi trong
tu sach » thu sach, su sach, te sach
tu manh » tu minh, tu hanh, vu manh

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 trien thuc cach khoin pho thong ) or ( tu manh trong thuc cachh khoan nhoi tong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach trien thuc cach khoin pho thong ) OR ( tu manh trong thuc cachh khoan nhoi tong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach trien thuc cach khoin pho thong ) or ( tu manh trong thuc cachh khoan nhoi tong ))*.