Perhaps you should try some spelling variations:
doan van » doan va, hoang van, luan van
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
va cau » van cau, va cac, va dau
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
cua tu » cua tuc, cua su, cua cu

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 ho. lieu va cau ((luc va) or (tuc va)) doan van ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x ho. lieu va cau ((luc va) OR (tuc va)) doan van ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x ho. lieu va cau ((luc va) or (tuc va)) doan van ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x ho. lieu va cau ((luc va) or (tuc va)) doan van ((cua te) OR (cua tu))*.