Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van nhan » van phan, danh nhan, van khanh
lang mai » lang dai, lang hai, lang man
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
ky lang » ky nang, ky dang, ky tang
tu bai » tu ban, tu bat, te bai
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
tu cai » tu cac, tu can, tu cay

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cai) OR (tu bai)) ky lang mai hoi. hieu ((van nhan) or (van thanh)) luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cai) OR (tu bai)) ky lang mai hoi. hieu ((van nhan) OR (van thanh)) luc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cai) OR (tu bai)) ky lang mai hoi. hieu ((van nhan) or (van thanh)) luc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cai) OR (tu bai)) ky lang mai hoi. hieu ((van nhan) or (van thanh)) luc va hanh vi cua tre*.