Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ca viet » va viet, co viet, hoa viet
ve cam » ve cham, ve cac, va cam
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
vi ca » vit ca, li ca, va ca

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