Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
sang ma » tang ma, nang ma, sang tao
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cac xuc » cam xuc, cac nuoc, chat xuc
ve su » va su

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 y ((nang xa) or (sang ma)) hoi. hieu va cac xuc ((va hanh) or (va danh)) ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((nang xa) OR (sang ma)) hoi. hieu va cac xuc ((va hanh) OR (va danh)) ve su triet.
• Adding a wildcard symbol may retrieve word variants: toc sach y ((nang xa) or (sang ma)) hoi. hieu va cac xuc ((va hanh) or (va danh)) ve su triet*.