Perhaps you should try some spelling variations:
trinh van » trinh han, trinh quan, trinh toan
vat trinh » va trinh, van trinh, viet trinh
thu sach » thuat sach, thuoc sach, thu hoach
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
tu sach » su sach, te sach, tu cach
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ty ((nang xa) or (nang x)) hoi. hieu van nam thuc vat trinh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty ((nang xa) OR (nang x)) hoi. hieu van nam thuc vat trinh van cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty ((nang xa) or (nang x)) hoi. hieu van nam thuc vat trinh van cua tre*.