Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
nang mai » nang ma, nang tai, lang mai
dinh dai » dinh dat, sinh dai, dinh dao
ty nang » ky nang, ty xang, ty hang
mai hoi » mai khoi, dai hoi, lai hoi
va nham » va cham, va tham, va nha
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet

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) or (doc sach)) ty nang mai hoi. lieu va nham thuc va dinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty nang mai hoi. lieu va nham thuc va dinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ty nang mai hoi. lieu va nham thuc va dinh dai cua tre*.