Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat sach » thuat lanh, thuat san
cao luc » bao luc, cao suc, cau luc
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
de cua » le cua, te cua, dieu cua
dau de » dau ve, dai de, sau de
va dau » va dao
v nang » va nang, vu nang, van nang
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) or (thuat sach)) v nang x hoi. hieu va ((cao luc) OR (cao duc)) va dau de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (thuat sach)) v nang x hoi. hieu va ((cao luc) OR (cao duc)) va dau de cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (thuat sach)) v nang x hoi. hieu va ((cao luc) OR (cao duc)) va dau de cua te".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (thuat sach)) v nang x hoi. hieu va ((cao luc) OR (cao duc)) va dau de cua te*.