Perhaps you should try some spelling variations:
khanh dai » thanh dat, khanh van, phan dai
dan khanh » dang khanh, van khanh, dat khanh
su triet » su viet, su tien, ve triet
thuc dan » thuc hanh, hoc dan, thuc vat
dam thuc » am thuc, dan thuc, nam thuc
hieu van » hieu va, thien van, hieu ve
toc sach » hoc sach, doc sach, thuoc sach
nang o » nang co, nang ho, nang ro
dai su » dai sua, dai so, dan su
o hoc » co hoc, mo hoc, so hoc

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) or (toc sach)) ky nang o hoc. ((hieu van) or (lieu va)) dam thuc dan khanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang o hoc. ((hieu van) OR (lieu va)) dam thuc dan khanh dai su triet.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang o hoc. ((hieu van) or (lieu va)) dam thuc dan khanh dai su triet*.