Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hang dien » quang dien, dang dieu, nhan dien
cau duc » cao duc, cau luc, chu duc
hanh de » hanh ve, hanh kem
su viet » so viet
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
nang o » nang co, nang ho, nang ro
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 ky nang o hoc. ((hieu va) OR (lieu va)) cau duc va ((hanh de) or (hang dien)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang o hoc. ((hieu va) OR (lieu va)) cau duc va ((hanh de) OR (hang dien)) su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang o hoc. ((hieu va) OR (lieu va)) cau duc va ((hanh de) or (hang dien)) su viet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang o hoc. ((hieu va) OR (lieu va)) cau duc va ((hanh de) or (hang dien)) su viet*.