Perhaps you should try some spelling variations:
phap sinh » phau sinh, phai sinh, phap tinh
thu sach » tu sach, thuat sach, thuoc sach
sinh bat » sinh vat, sinh ban, sinh hoat
hieu van » hieu va, thien van, lieu va
lam hoc » am hoc, lam hoa, lam thuoc
bat cua » ban cua, mat cua, bai cua
tam hoc » tam hon, am hoc, tam ho
lang ha » long ha
sach ky » sac ky, sach y, sach ty
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: thu sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap sinh bat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((lang ha) OR (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap sinh bat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap sinh bat cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap sinh bat cua tre*.