Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
lang van » dang van, tang van, hoang van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac hoc » cach hoc, cac hop, bac hoc
va hanh » van hanh, va thanh, va danh
vi va » vi van, vai va, vu va

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 ky ((nang xa) or (lang van)) hoi. hieu van ((cac nuoc) or (cac hoc)) va hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (lang van)) hoi. hieu van ((cac nuoc) OR (cac hoc)) va hanh vi va triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang van)) hoi. hieu van ((cac nuoc) or (cac hoc)) va hanh vi va triet*.