Perhaps you should try some spelling variations:
dung van » duong van, dung va, dang van
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
cua viet » ca viet, hoa viet, cua dieu
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
ve pham » v pham, ve phan, ve phat
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. hieu ((ve pham) OR (vi pham)) dung van hanh tai ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu ((ve pham) OR (vi pham)) dung van hanh tai ((cua viet) OR (cua vat)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu ((ve pham) OR (vi pham)) dung van hanh tai ((cua viet) or (cua vat))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu ((ve pham) OR (vi pham)) dung van hanh tai ((cua viet) or (cua vat))*.