Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
thuc day » thuc dan, thuc vat
danh hai » dang hai, lanh hai, manh hai
te sach » toc sach
sach ty » sach y, sach tu, sach thu
thuc va » thuc vat, thuc dan
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
nang o » nang co, nang ho, nang ro
va am » va lam, va cam
o hai » co hai, so hai, o lai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang o hai. hieu va am ((thuc va) OR (thuc day)) danh hai ((cua triet) OR (cua viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang o hai. hieu va am ((thuc va) or (thuc day)) danh hai ((cua triet) OR (cua viet))~".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang o hai. hieu va am ((thuc va) or (thuc day)) danh hai ((cua triet) OR (cua viet))*.