Perhaps you should try some spelling variations:
phap trinh » phap tinh, lap trinh, phap dinh
phap sinh » phau sinh, phai sinh, phap tinh
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van cua » vang cua, ban cua, dan cua
lam hoc » am hoc, lam hoa, tam hoc
sach ky » sac ky, sach y, sach ty
van lam » van nam
nang xa » lang xa, nang ma, mang xa
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: te sach ky ((nang xa) or (nang x)) hoi. hieu van lam hoc ((phap trinh) OR (phap sinh)) van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (nang x)) hoi. hieu van lam hoc ((phap trinh) OR (phap sinh)) van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (nang x)) hoi. hieu van lam hoc ((phap trinh) OR (phap sinh)) van cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (nang x)) hoi. hieu van lam hoc ((phap trinh) OR (phap sinh)) van cua tre*.