Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van hanh » van thanh, ban hanh, van anh
chat loc » chat hoc, chat doc, chat long
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
loc van » luoc van, hoc van, lo van
2 danh » 1 danh
2 dang » _ dang, b dang, o dang
vi cua » vai cua, di cua

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 ((2 dang) OR (2 danh)) xay hoi. hieu va chat loc van hanh ((vi cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((2 dang) OR (2 danh)) xay hoi. hieu va chat loc van hanh ((vi cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((2 dang) OR (2 danh)) xay hoi. hieu va chat loc van hanh ((vi cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((2 dang) OR (2 danh)) xay hoi. hieu va chat loc van hanh ((vi cua) or (dai cua)) tre*.