Perhaps you should try some spelling variations:
sach cach » sach danh, sach cap, cac cach
cach thuc » anh thuc, cac thu
thuc canh » thuc hanh, thu canh, thuc cach
canh khoa » xanh khoa, doanh khoa, chinh khoa
sach tri » sach tai, sach tren, sach truc
tri thuy » thi thuy, tri thuc, trinh thuy
thuy anh » thuy linh
anh khoa » doanh khoa, hang khoa
khoa pho » khoa phu, khoa khoa, khoa phau
tu sach » thu sach, su sach, te sach
so sach » so sanh, bo sach, co sach
khoa he » hoa he, khoa hoc, khong he

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 tri thuy anh khoa pho thong ) or ( so sach cach thuc canh khoa he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tri thuy anh khoa pho thong ) OR ( so sach cach thuc canh khoa he thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tri thuy anh khoa pho thong ) or ( so sach cach thuc canh khoa he thong ))*.