Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, lieu va
van cam » van nam, van lam, van cau
tuc gia » tac gia, duc gia, toc gia
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach ty, sach kem
nang o » nang co, nang ho, nang ro
cua tu » cua tuc, cua su, cua cu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sach y)) nang o hoi. hieu van cam tuc gia ((thanh dai) or (doanh tai)) cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang o hoi. hieu van cam tuc gia ((thanh dai) OR (doanh tai)) cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) nang o hoi. hieu van cam tuc gia ((thanh dai) or (doanh tai)) cua tu*".