Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
truc va » thuc va, thuc vat, trung va
va tinh » may tinh
ve cac » va cac, vien cac
va cua » va chua, via cua, ma cua
ca cua » co cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang xa hoi. hieu ve cac truc va tinh ((va cua) or (ca cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. hieu ve cac truc va tinh ((va cua) OR (ca cua)) tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. hieu ve cac truc va tinh ((va cua) or (ca cua)) tre*.