Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cua ngan » cua ban, vu ngan, cua dan
cuu ngan » cuu nhan, cuu nan, cuu ngon
bang va » hang va, ban va, trang va
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ty nang » ky nang, ty hang, ly nang
ve cham » va cham, ve chat, vu cham
va dau » va dao

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 ((ty nang) or (ty xang)) xa hoi. hieu ve cham ((cuu ngan) OR (cua ngan)) bang va dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu ve cham ((cuu ngan) OR (cua ngan)) bang va dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ty xang)) xa hoi. hieu ve cham ((cuu ngan) OR (cua ngan)) bang va dau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) xa hoi. hieu ve cham ((cuu ngan) OR (cua ngan)) bang va dau tren*.