Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thien van » thi van
tu sach » thu sach, su sach, te sach
nang ro » nang co, nang ho, nang ra
lam duc » lam duoc, pham duc, nam duoc
luu tre » luu tru, cuu tre, luy tre
y nang » ky nang, ly nang, v nang
ro hoi » co hoi, o hoi, mo hoi
va don » va dong, va doc, va do
vi luu » vi lua

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 (thuoc sach)) y nang ro hoi. ((lieu va) or (thien van)) lam duc va don vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) y nang ro hoi. ((lieu va) OR (thien van)) lam duc va don vi luu tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) y nang ro hoi. ((lieu va) or (thien van)) lam duc va don vi luu tre*.