Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
nuoc van » nuoc va, luoc van, nuoc dan
nuoc san » nuoc luan, nguoi san, nuoc quan
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
cua tre » cua te, cuu tre, dua tren

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 ky lang xa hoi. hieu va tham ((nuoc van) OR (nuoc san)) hanh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu va tham ((nuoc van) OR (nuoc san)) hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. hieu va tham ((nuoc van) OR (nuoc san)) hanh vi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu va tham ((nuoc van) OR (nuoc san)) hanh vi ((cua tre) or (cua triet))*.