Perhaps you should try some spelling variations:
va nghiep » va nghien, lam nghiep, cac nghiep
khien hoc » nhiet hoc
nghiep tu » nghiep vu, nghiep vua, nghiep cua
sach dat » sach dao, sach danh, sach bai
dat nghe » day nghe, da nghe, dang nghe
dien hoc » dien hoa, tin hoc, lieu hoc
hoach va » hoach xay, hanh va, doanh va
tu sach » thu sach, su sach, te sach
tu hoc » te hoc
d hoc » du hoc, ad hoc, de hoc

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 dat nghe ((d hoc) or (((dien hoc) or (khien hoc)))) ) or ( thu hoach va nghiep tu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach dat nghe ((d hoc) OR (((dien hoc) OR (khien hoc)))) ) OR ( thu hoach va nghiep tu hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach dat nghe ((d hoc) or (((dien hoc) or (khien hoc)))) ) or ( thu hoach va nghiep tu hoc ))*.