Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cua triet » cua viet, su triet, va triet
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
va hanh » van hanh, va thanh, va danh
ca viet » va viet, co viet, hoa viet
cuu tre » cua tre, cau tren, cau treo
sach ty » sach y, sach tu, sach thu
dai dac » dam dac, dai mac, dai dich
ty nang » ky nang, ty xang, ty hang
nang o » nang co, nang ho, nang ro
dac va » duc va, day va, dat va
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ty nang o hoi. hieu vien dai dac va hanh vi ((((cua triet) or (ca viet))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty nang o hoi. hieu vien dai dac va hanh vi ((((cua triet) OR (ca viet))) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: thuat sach ty nang o hoi. hieu vien dai dac va hanh vi ((((cua triet) or (ca viet))) or (cuu tre))*.