Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
tham loc » tham nuoc, cham soc, hau loc
vu sach » vu bach, su sach, vu khach
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
loc va » hoc va, luc va
vi hoa » voi hoa, vi hoc, va hoa
x hoi » xa hoi, o hoi, x ho

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: ((toc sach) OR (vu sach)) y nang x hoi. hieu van tham loc va hanh vi hoa viet~.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (vu sach)) y nang x hoi. hieu van tham loc va hanh vi hoa viet*.