Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu quan » hieu qua, lieu quan, thien quan
quan dat » quan sat, qua dat, quan dac
dat duoc » dat nuoc, da duoc, luat duoc
duoc van » duoc va, duc van, duoc ban
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang ca » dang cac, dan ca, hang ca
ca phoi » cap phoi, cay phoi, gap phoi
hanh ve » hanh va, hanh kem

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 dang ca phoi. hieu quan dat duoc van ((hanh ve) OR (hanh vi)) cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky dang ca phoi. hieu quan dat duoc van ((hanh ve) OR (hanh vi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky dang ca phoi. hieu quan dat duoc van ((hanh ve) OR (hanh vi)) cau tren*.