Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
va huong » va thuong, va phuong, va tuong
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
dan cuu » dan cua, dan luu, dinh cuu
cac tu » cac thu, cach tu, cac du
dan cu » dan cua, dan ca, dan su

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

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