Perhaps you should try some spelling variations:
dang ngoc » hoang ngoc, van ngoc, dang nghe
dat ngoc » dat nuoc, dau ngoc, doan ngoc
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu le » hieu ve, hieu he, hieu ly
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
vi cuu » vinh cuu
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang xa hoi. hieu le ((dat ngoc) OR (dang ngoc)) va hanh ((vi cuu) or (vi luu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. hieu le ((dat ngoc) OR (dang ngoc)) va hanh ((vi cuu) OR (vi luu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang xa hoi. hieu le ((dat ngoc) OR (dang ngoc)) va hanh ((vi cuu) or (vi luu)) tre".
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. hieu le ((dat ngoc) OR (dang ngoc)) va hanh ((vi cuu) or (vi luu)) tre*.