Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
ban hanh » ban hang
phan dai » phan dau, phan day, phan loai
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
dai ban » dai han, tai ban, di ban
ty lang » tay lang, ty xang, tu lang
va phan » van phan, va phat, va phap
vi su » va su, ve su, oi su
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: nuoc sach ((ty lang) or (ty hang)) xa hoi. hieu va phan dai ban hanh ((vi su) or (ki su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nuoc sach ((ty lang) OR (ty hang)) xa hoi. hieu va phan dai ban hanh ((vi su) OR (ki su)) triet.
• Adding a wildcard symbol may retrieve word variants: nuoc sach ((ty lang) or (ty hang)) xa hoi. hieu va phan dai ban hanh ((vi su) or (ki su)) triet*.