Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
lang van » dang van, tang van, hoang van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hac luc » nhan luc, than luc
va hanh » van hanh, va thanh, va danh
luc va » duc va, tuc va, loc va
vai su » van su, lai su, tai su
va hac » van hac, va khac, va cac

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 ky ((nang x) or (lang van)) hoi. hieu va hac luc va hanh ((vai su) OR (va su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang x) OR (lang van)) hoi. hieu va hac luc va hanh ((vai su) OR (va su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky ((nang x) or (lang van)) hoi. hieu va hac luc va hanh ((vai su) OR (va su)) triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang x) or (lang van)) hoi. hieu va hac luc va hanh ((vai su) OR (va su)) triet*.