Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
ve pham » vi pham, v pham, ve phat
ve phan » va phan, ke phan, ve phat
su viet » so viet
y nang » ky nang, ly nang, v nang
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: tu sach y nang ma hoa. hieu ((ve pham) OR (ve phan)) duy ((van thanh) or (ban hanh)) vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoa. hieu ((ve pham) OR (ve phan)) duy ((van thanh) OR (ban hanh)) vi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ma hoa. hieu ((ve pham) OR (ve phan)) duy ((van thanh) or (ban hanh)) vi su viet*".