Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, te sach, tu cach
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang
su sach » so sach, vu sach
cuu tre » cua tre, cau tren, cau treo
luc va » duc va, tuc va, loc va
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ly nang xa hoi. hieu van cam ((luc va) or (thuc dan)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ly nang xa hoi. hieu van cam ((luc va) OR (thuc dan)) hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ly nang xa hoi. hieu van cam ((luc va) or (thuc dan)) hanh vi cuu tre*.