Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hang dien » quang dien, dang dieu, nhan dien
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, ve triet
van cam » van nam, van lam, van cau
sach ty » sach y, sach tu, sach thu
cam duc » cam xuc, cao duc, pham duc
hanh de » hanh ve, hanh kem
ty nang » ky nang, ty xang, ty hang
o hoi » co hoi, o hai, o hoa
o hoc » co hoc, mo hoc, so hoc

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) or (o hoc)). hieu van cam duc va ((hanh de) or (hang dien)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty nang ((o hoi) OR (o hoc)). hieu van cam duc va ((hanh de) OR (hang dien)) su triet.
• Adding a wildcard symbol may retrieve word variants: thuat sach ty nang ((o hoi) or (o hoc)). hieu van cam duc va ((hanh de) or (hang dien)) su triet*.