Perhaps you should try some spelling variations:
sang than » cang thang, dang thanh, sang tao
sang tai » sang tao, tang tai, dung tai
hang tai » hang va, dung tai
te sach » toc sach
luc van » luoc van, luu van, luc va
tai cuu » tai cuc, tai buu, tai cua
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((sang tai) OR (sang than)) khoa. hieu ve cam ((luc van) or (duc van)) hang tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((sang tai) OR (sang than)) khoa. hieu ve cam ((luc van) OR (duc van)) hang tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((sang tai) OR (sang than)) khoa. hieu ve cam ((luc van) or (duc van)) hang tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((sang tai) OR (sang than)) khoa. hieu ve cam ((luc van) or (duc van)) hang tai cuu tre*.