Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
hang di » hang doi, hang vi, hang dien
hanh de » hanh ve, hanh kem
lam duc » lam duoc, pham duc, nam duoc
van lam » van nam
sach ky » sac ky, sach y, sach ty
nang ro » nang co, nang ho, nang ra
su viet » so viet
nang o » nang co, nang ho, nang x

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) OR (nang ro)) hoi. hieu van lam duc va ((hanh de) or (hang di)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky ((nang o) OR (nang ro)) hoi. hieu van lam duc va ((hanh de) OR (hang di)) su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky ((nang o) OR (nang ro)) hoi. hieu van lam duc va ((hanh de) or (hang di)) su viet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky ((nang o) OR (nang ro)) hoi. hieu van lam duc va ((hanh de) or (hang di)) su viet*.