Perhaps you should try some spelling variations:
trinh dieu » trinh dien, tinh dieu, trinh dinh
cham thuc » nham thuc, pham thuc, tham thuc
van trinh » van thinh, van tinh, dan trinh
doc sach » hoc sach, toc sach, nuoc sach
thuc van » thuc vat, thuc dan, thuc va
dieu tra » dieu tri, kiem tra, dieu cua
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va cham » va chat, va tham
tra tre » tran tren, tran tri, tran tro

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 lang xa hoi. hieu va cham thuc van trinh dieu tra tre~.
• Adding a wildcard symbol may retrieve word variants: doc sach ty lang xa hoi. hieu va cham thuc van trinh dieu tra tre*.