Perhaps you should try some spelling variations:
huong doi » huong dan, trong doi, dung doi
dam thuc » am thuc, dan thuc, dai thuc
xa huong » xa phuong, va huong, xa muong
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
doi cua » dai cua, hoi cua
ty nang » ky nang, ty hang, ly nang
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) or (nam thuc)) xa huong doi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) OR (nam thuc)) xa huong doi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) or (nam thuc)) xa huong doi cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) or (nam thuc)) xa huong doi cua te*.