Perhaps you should try some spelling variations:
ban benh » san benh, ban banh, can benh
su triet » su viet, su tien, ve triet
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
van cao » van bao, van hao, van cau
ba benh » va benh, bo benh, bach benh
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
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 y nang ma hoi. hieu ((van cao) or (van dao)) quoc ((ban benh) OR (ba benh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoi. hieu ((van cao) OR (van dao)) quoc ((ban benh) OR (ba benh)) vi su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ma hoi. hieu ((van cao) or (van dao)) quoc ((ban benh) OR (ba benh)) vi su triet*".