Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dinh tri » chinh tri
tri cuu » tri cua, tra cuu, trinh cuu
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
sang ma » tang ma, nang ma, sang tao
cuu tre » cua tre, cau tren, cau treo
va cam » va cham, va cac, va cao
xac va » tac va, ac va, bac va
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((nang x) or (sang ma)) hoi. hieu va cam ((xac va) or (tuc va)) dinh tri cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang x) OR (sang ma)) hoi. hieu va cam ((xac va) OR (tuc va)) dinh tri cuu tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang x) or (sang ma)) hoi. hieu va cam ((xac va) or (tuc va)) dinh tri cuu tre*.