Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
thi hong » thi cong, thi phuong, thi hanh
van hanh » van thanh, ban hanh, van anh
chieu tu » chieu tro, lieu tu, chu tu
cau tren » cu tren, dau tren, ca tren
doc sach » hoc sach, nuoc sach, dac sac
ty nang » ky nang, ty xang, ty hang
tu cham » toc cham, thi cham
cham oc » cham soc, cham o, cham hoi
oc van » hoc van, luoc van, quoc van
vi cau » va cau, ve cau, di cau

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) OR (doc sach)) ((ty nang) or (thi hong)) xa hoi. chieu tu cham oc van hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ((ty nang) OR (thi hong)) xa hoi. chieu tu cham oc van hanh vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ((ty nang) or (thi hong)) xa hoi. chieu tu cham oc van hanh vi cau tren".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ((ty nang) or (thi hong)) xa hoi. chieu tu cham oc van hanh vi cau tren*.