Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
tham tuc » tham thuc, thai tuc, nham thuc
sinh dai » sinh thai, si dai, sinh vat
sach ty » sach y, sach tu, sach thu
hang ma » hang va, tang ma, nang ma
hang ca » hang va, nang cao, hang tai
va tham » van tham, va cham, va thanh
va sinh » va kinh, va tinh, vi sinh
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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 ty ((hang ma) or (hang ca)) hoi. lieu va tham tuc va sinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty ((hang ma) OR (hang ca)) hoi. lieu va tham tuc va sinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sach ty ((hang ma) or (hang ca)) hoi. lieu va tham tuc va sinh dai cua tre*.