Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cua viet » hoa viet, cua vat, cua dieu
bach xuc » bach tuoc, bach xuan, bach hue
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
tu nano » truc nano
tu nang » tru nang, tu nong, tu lang
ca viet » va viet, co viet, hoa viet
xuc va » duc va, tuc va, luc va

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 (tu nano)) mai hoi. hieu vien bach xuc va hanh vi ((cua viet) OR (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tu nang) OR (tu nano)) mai hoi. hieu vien bach xuc va hanh vi ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu nang) or (tu nano)) mai hoi. hieu vien bach xuc va hanh vi ((cua viet) OR (ca viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu nang) or (tu nano)) mai hoi. hieu vien bach xuc va hanh vi ((cua viet) OR (ca viet))*.