Perhaps you should try some spelling variations:
quan phan » quang phan, luan phan, qua phan
hieu quan » hieu qua, lieu quan, thien quan
phan pham » phan phat, phan ham, phan phan
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
te sach » toc sach
sach ky » sac ky, sach y, sach ty
mang xa » lang xa, mang may, dang xay
nang ma » tang ma, sang ma, nang cao
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((mang xa) or (nang ma)) hoi. hieu quan phan pham van hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((mang xa) OR (nang ma)) hoi. hieu quan phan pham van hanh vi su triet.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((mang xa) or (nang ma)) hoi. hieu quan phan pham van hanh vi su triet*.