Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
duc ca » duc cac, duc va, duc ha
ca dan » cac dan, ca dao
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky ((nang xa) OR (nang ma)) hoi. ((lieu va) OR (hieu qua)) pham duc ca dan vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky ((nang xa) OR (nang ma)) hoi. ((lieu va) OR (hieu qua)) pham duc ca dan vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky ((nang xa) OR (nang ma)) hoi. ((lieu va) OR (hieu qua)) pham duc ca dan vi cua tre*.