Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
doanh dan » doanh ban, doanh van, doanh dao
thu sach » tu sach, thuat sach, thuoc sach
hien cam » hien cac, hien cau, hien giam
truc va » thuc va, thuc vat, trung va
dan cua » dan ca, ban cua, dai cua
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cua tuc » cua duc, cua tu, cua thuoc
xac va » tac va, ac va, bac va
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang ma hoi. dieu hien cam ((xac va) OR (truc va)) doanh dan cua tuc~.
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang ma hoi. dieu hien cam ((xac va) or (truc va)) doanh dan cua tuc*.