Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua dieu
va nang » van nang, da nang, cam nang
nang di » nang du, hang di, nang ji
y nang » ky nang, ly nang, v nang
cam lo » nam lo, cam ly, cam o
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang x hoi. thien van ((cam loc) or (cam lo)) va nang di ((cua viet) OR (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang x hoi. thien van ((cam loc) OR (cam lo)) va nang di ((cua viet) OR (cua vat))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x hoi. thien van ((cam loc) or (cam lo)) va nang di ((cua viet) OR (cua vat))*".