Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
su triet » su viet, su tien
danh den » danh dien, dan den, danh yen
sach cam » sach cap, mach cam, sach tham
ve triet » va trien
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
nang xa » nang x, lang xa, nang ma
cham o » cham soc
o va » do va, so va, co va

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 cam nang xa hoi. ((hieu va) or (hieu van)) cham o va danh den ((su triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach cam nang xa hoi. ((hieu va) OR (hieu van)) cham o va danh den ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach cam nang xa hoi. ((hieu va) or (hieu van)) cham o va danh den ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach cam nang xa hoi. ((hieu va) or (hieu van)) cham o va danh den ((su triet) OR (ve triet))*.