Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cham loc » cham soc, chon loc, cham o
cau treo » cau theo, cau tren, cau triet
va nang » van nang, da nang, cam nang
hieu va » lieu va, hieu qua
hieu su » hieu sau, tieu su, hieu so
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
ma hoi » mai hoi, xa hoi, ma hoa
v nang » vu nang, van nang, voi nang
loc va » hoc va, luc va
di cau » da cau, diem cau

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