Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thu hang » thuc hanh, thu huong, thu trang
thi hang » thi hanh, thi nang, thi hong
ban hanh » ban hang
hieu ve » hieu va, hieu van
ve chao » ve chat, ve cham, ve cho
doi cua » dai cua, hoi cua
xu ban » xuc ban, tu ban, vu ban
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: doc sach ((thu hang) or (thi hang)) xa hoi. hieu ve chao xu ban hanh ((vi cua) or (doi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((thu hang) OR (thi hang)) xa hoi. hieu ve chao xu ban hanh ((vi cua) OR (doi cua)) triet.
• Adding a wildcard symbol may retrieve word variants: doc sach ((thu hang) or (thi hang)) xa hoi. hieu ve chao xu ban hanh ((vi cua) or (doi cua)) triet*.