Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
ban thanh » ban hanh, ban hang
toc sach » hoc sach, thuoc sach, nuoc sach
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
doc sach » hoc sach, nuoc sach, dac sac
ty nang » ky nang, ty xang, ty hang
mai hoi » mai khoi, dai hoi, lai hoi
van cam » van nam, van lam, van cau
cam dua » ca dua, cay dua, chay dua
dua ban » dia ban, cua ban, qua ban
cuc tre » cua tre, cuu tre, cuc thue
duc tre » duoc tren, duc tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (doc sach)) ty nang mai hoi. hieu van cam dua ban thanh hai ((cuc tre) or (duc tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty nang mai hoi. hieu van cam dua ban thanh hai ((cuc tre) OR (duc tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty nang mai hoi. hieu van cam dua ban thanh hai ((cuc tre) or (duc tre))".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty nang mai hoi. hieu van cam dua ban thanh hai ((cuc tre) or (duc tre))*.