Perhaps you should try some spelling variations:
tru nang » tra nang, tri nang, truc nano
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
tu nang » tu nong, tu nano, tu lang
nam xua » nam cua, nam mua, nam qua
xua ban » xuat ban, cua ban, qua ban
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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 ((tu nang) OR (tru nang)) xa hoi. hieu van nam xua ban hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tu nang) OR (tru nang)) xa hoi. hieu van nam xua ban hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu nang) OR (tru nang)) xa hoi. hieu van nam xua ban hanh vi ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu nang) OR (tru nang)) xa hoi. hieu van nam xua ban hanh vi ((cua tre) or (cua te))*.