Perhaps you should try some spelling variations:
phan pham » phan phat, phan ham, phan phan
quan phan » quang phan, luan phan, qua phan
hieu quan » hieu qua, lieu quan, thien quan
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
toc sach » hoc sach, doc sach, thuoc sach
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) OR (toc 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) OR (toc sach)) ky ((mang xa) OR (nang ma)) hoi. hieu quan phan pham van hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc 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) OR (toc sach)) ky ((mang xa) or (nang ma)) hoi. hieu quan phan pham van hanh vi su triet*.