Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va trien » va truyen, va thiet, va tuyen
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
v nang » va nang, vu nang, van nang
xuc va » duc va, tuc va, luc va
di va » dai va, di vao, doi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sinh) or (doc sach)) v nang xa hoi. ((hieu va) or (lieu va)) cam xuc va hanh di va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sinh) OR (doc sach)) v nang xa hoi. ((hieu va) OR (lieu va)) cam xuc va hanh di va trien.
• Adding a wildcard symbol may retrieve word variants: ((hoc sinh) or (doc sach)) v nang xa hoi. ((hieu va) or (lieu va)) cam xuc va hanh di va trien*.