Perhaps you should try some spelling variations:
thien van » thi van
nam thuoc » nam thuc, nha thuoc, cay thuoc
lanh day » lanh dao, lanh lay, danh dau
day cua » dai cua
va lanh » va lang, va danh, va hanh
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
o hai » co hai, so hai, o lai

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: tu ((sach ky) OR (sac ky)) nang o hai. thien van ((nam thuoc) OR (nam thu)) va lanh day cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang o hai. thien van ((nam thuoc) or (nam thu)) va lanh day cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang o hai. thien van ((nam thuoc) or (nam thu)) va lanh day cua tre*.