Perhaps you should try some spelling variations:
phu thong » pho thong, phap thong, khau thong
thuc cach » thuoc sach, truoc cach, thuc hanh
cach khoa » bach khoa, cac khoa, cac khoan
khoa toan » khoa than, hoa toan, khoa luan
sach dan » sach danh, sach dao, sach dat
dan thuc » dan toc, am thuc
thuc cac » tuc cac, phuc cac, thac cac
cac khoi » cac thoi, cac khoan, cach thoi
khoi phu » hoi phu, khoa phu, khoe phu
dao thuc » dao tuc, do thuc, bao thuc
su sach » so sach, vu sach
tu lanh » tu hanh, tu lenh, tu manh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach dan thuc cac khoi phu thong ) or ( tu lanh dao thuc cach khoa toan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach dan thuc cac khoi phu thong ) OR ( tu lanh dao thuc cach khoa toan thong )).
• Adding a wildcard symbol may retrieve word variants: (( su sach dan thuc cac khoi phu thong ) or ( tu lanh dao thuc cach khoa toan thong ))*.