Perhaps you should try some spelling variations:
thien van » thi van
cua viet » hoa viet, cua vat, cua dieu
van chat » cao chat
dung sai » dung tai, dung va, dung dat
tu sach » thu sach, su sach, te sach
ca viet » va viet, co viet, hoa viet
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
loc va » luc va
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ma hoi. thien van chat ((hoc va) or (loc va)) dung sai ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. thien van chat ((hoc va) OR (loc va)) dung sai ((cua viet) OR (ca viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. thien van chat ((hoc va) or (loc va)) dung sai ((cua viet) or (ca viet))*.