Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thi hanh » thi thanh
su triet » su tien, ve triet
dang xay » dang van, van xay
xay hoi » xa hoi, tay hoi, cay phoi
thi van » thi lan, thi nang
nam sua » nam cua, nam suu, nam mua
va hanh » van hanh, va thanh, va danh
su viet » so viet
sach o » sach lo, sac o, sach y
sua va » suat va, vua va, xua va
o dang » xo dang, do dang, so dang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach o dang xay hoi. ((thi van) or (thi hanh)) nam sua va hanh vi ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach o dang xay hoi. ((thi van) OR (thi hanh)) nam sua va hanh vi ((su triet) OR (su viet)).
• Adding a wildcard symbol may retrieve word variants: hoc sach o dang xay hoi. ((thi van) or (thi hanh)) nam sua va hanh vi ((su triet) or (su viet))*.