Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thanh vai » thanh hai, thanh van, thanh tai
van thanh » ban thanh, van tuan
vien cac » vien bach, vien dai, vien da
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
duc van » duc va, duc tan, duc manh
sach ky » sac ky, sach y, sach ty
vai va » mai va, dai va, hai va
ve cac » va cac
ve cam » ve cham, va cam, ve cai
ma hoi » mai hoi, xa hoi, ma hoa
thiet » thieu

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 tang ma hoi. hieu ((ve cam) or (((ve cac) OR (vien cac)))) duc van thanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky tang ma hoi. hieu ((ve cam) OR (((ve cac) OR (vien cac)))) duc van thanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky tang ma hoi. hieu ((ve cam) or (((ve cac) OR (vien cac)))) duc van thanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky tang ma hoi. hieu ((ve cam) or (((ve cac) OR (vien cac)))) duc van thanh vai va thiet*.