Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va danh » va dinh, va dan, va hanh
lam loc » lam duoc, lam ngoc
sach ly » sach y, sach lo, sach ty
hieu va » lieu va, hieu qua
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, ma hoa, me hoi
loc va » hoc va, luc va
va lam » van lam, va lap
du cu » su cu, da cu
cu cu » cu cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ly nang ((ma hoi) or (xa hoi)). hieu va lam loc va danh ((du cu) OR (cu cu)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ly nang ((ma hoi) OR (xa hoi)). hieu va lam loc va danh ((du cu) OR (cu cu)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ly nang ((ma hoi) or (xa hoi)). hieu va lam loc va danh ((du cu) OR (cu cu)) tren".
• Adding a wildcard symbol may retrieve word variants: thu sach ly nang ((ma hoi) or (xa hoi)). hieu va lam loc va danh ((du cu) OR (cu cu)) tren*.