Perhaps you should try some spelling variations:
lam thuoc » nam thuoc, cay thuoc, nam thuc
trinh vat » trinh van, trinh luat, sinh vat
thu sach » tu sach, thuat sach, thuoc sach
va trinh » van trinh, va tinh, lap trinh
hieu van » hieu va, thien van, lieu va
vat cua » mat cua, bat cua, dat cua
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (nang x)) hoi. hieu van ((lam thuoc) or (am thuc)) va trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang x)) hoi. hieu van ((lam thuoc) OR (am thuc)) va trinh vat cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (nang x)) hoi. hieu van ((lam thuoc) or (am thuc)) va trinh vat cua tre*.