Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
cam truc » cau truc, nam truc, lam truoc
tu sach » thu sach, su sach, te sach
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
vu sach » vu bach, su sach, vu khach

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) or (vu sach)) ty nang xa hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ty nang xa hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (vu sach)) ty nang xa hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ty nang xa hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai cuu tre*.