Perhaps you should try some spelling variations:
cay thuoc » cua thuoc, nam thuoc, va thuoc
thuoc lap » thuoc la, thuoc luan, thuoc phap
trinh cua » tinh cua, trinh luat, trinh quan
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
cuu tre » cua tre, cau treo
va cay » va cac, va cao, va cai

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 ky ((nang xa) or (nang x)) hoi. lieu va cay thuoc lap trinh cua ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang x)) hoi. lieu va cay thuoc lap trinh cua ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang x)) hoi. lieu va cay thuoc lap trinh cua ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang x)) hoi. lieu va cay thuoc lap trinh cua ((cuu tre) OR (cau tren))*.