Perhaps you should try some spelling variations:
phap trinh » phap tinh, lap trinh, phap sinh
trinh vat » trinh van, trinh luat, sinh vat
hieu van » hieu va, thien van, lieu va
te sach » toc sach
lam hoc » am hoc, lam hoa, lam thuoc
vat cua » mat cua, bat cua, dat 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: te sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((lang ha) OR (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap trinh vat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap trinh vat cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((lang ha) or (nang x)) hoi. hieu van ((lam hoc) OR (tam hoc)) phap trinh vat cua tre*.