Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van nang » van quang, van ban, van dong
cham loc » cham soc, chon loc, cham o
hieu su » hieu sau, tieu su, hieu so
danh du » danh dau, danh tu, dinh du
va danh » va dinh, va dan, va hanh
cuu tre » cua tre, cau tren, cau treo
hieu vu » hieu va, hieu ve, dieu vu
loc va » hoc va, luc va
v nang » va nang, vu nang, voi nang
du cuu » tu cuu

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 ((v nang) OR (van nang)) xa hoi. ((hieu vu) or (hieu su)) cham loc va danh du cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((v nang) OR (van nang)) xa hoi. ((hieu vu) OR (hieu su)) cham loc va danh du cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ((v nang) OR (van nang)) xa hoi. ((hieu vu) or (hieu su)) cham loc va danh du cuu tre".
• Adding a wildcard symbol may retrieve word variants: doc sach ((v nang) OR (van nang)) xa hoi. ((hieu vu) or (hieu su)) cham loc va danh du cuu tre*.