Perhaps you should try some spelling variations:
va phuong » va thuong, cac phuong
toc sach » hoc sach, doc sach, thuoc sach
doi cuoc » doc cuoc, doi cua, dao cuoc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
doi cuu » doi cua
cac tu » cac thu, cach tu, cac du

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. ((hieu va) or (hieu qua)) cac tu va phuong ((doi cuu) OR (doi cuoc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. ((hieu va) OR (hieu qua)) cac tu va phuong ((doi cuu) OR (doi cuoc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. ((hieu va) or (hieu qua)) cac tu va phuong ((doi cuu) OR (doi cuoc)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. ((hieu va) or (hieu qua)) cac tu va phuong ((doi cuu) OR (doi cuoc)) tre*.