Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cham tuc » nham thuc, pham thuc, tham thuc
thi van » thi lan, thi hanh, thi nang
dinh cu » dinh cuu, dinh chuc, dinh chau
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
tuc va » thuc va, truc va, tuc xa
cu cua » cau cua, ca cua, co cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach y ((nang xa) OR (lang xa)) hoi. ((thien van) or (thi van)) cham tuc va dinh cu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y ((nang xa) OR (lang xa)) hoi. ((thien van) OR (thi van)) cham tuc va dinh cu cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach y ((nang xa) OR (lang xa)) hoi. ((thien van) or (thi van)) cham tuc va dinh cu cua tre".
• Adding a wildcard symbol may retrieve word variants: doc sach y ((nang xa) OR (lang xa)) hoi. ((thien van) or (thi van)) cham tuc va dinh cu cua tre*.