Perhaps you should try some spelling variations:
phap thong » phap phong, phap chong, phap tieng
sach truc » cach thuc, sach tren, sach thu
canh khoa » anh khoa, xanh khoa, doanh khoa
pho thong » he thong
khoa phap » khoa phau, khoan phai, khong phap
khoa pho » khoa phu, khoa khoa, khoa phau
toc sach » hoc sach, doc sach, thuoc sach
cac khoa » cac khoan, cac khoi, dac khoa
tu sach » thu sach, su sach, te sach
truc ve » thuc ve, truc va, truc van
ve canh » van canh, ve thanh
truc te » thuc te, truc tu, truc tiep
te cac » tu cac, ve cac, te cao

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 truc ve canh khoa pho thong ) or ( toc sach truc te cac khoa phap thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach truc ve canh khoa pho thong ) OR ( toc sach truc te cac khoa phap thong ))*.