Perhaps you should try some spelling variations:
khoan phai » khong phai, khoa phau, khoan hoi
phai thong » phap thong, phai tuong, phan thong
tri thuoc » tri thuc, tri hoc, tin thuoc
thuoc anh » thuoc thanh, thuoc dang, thuoc sach
sach tri » sach tai, sach tren, sach truc
toc sach » hoc sach, doc sach, thuoc sach
anh khoa » doanh khoa, hang khoa
vu sach » vu bach, su sach, vu khach
khoa he » hoa he, khoa hoc, khong he
tri ve » tri va, tri le, trinh ve
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu sach tri ve cac khoan phai thong ) or ( toc sach tri thuoc anh khoa he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach tri ve cac khoan phai thong ) OR ( toc sach tri thuoc anh khoa he thong )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach tri ve cac khoan phai thong ) or ( toc sach tri thuoc anh khoa he thong ))*.