Perhaps you should try some spelling variations:
trinh ngan » chinh ngan, trinh han, trinh quan
hoc trinh » doc trinh, hoc tinh, hoc sinh
ky huyet » ly huyet, cay huyet
sach han » sach tham, sach danh, sach nang
thuat co » thuat do, thuat o
hoc hoc » hoc hoa, toc hoc, hoc hoi
su sach » so sach, vu sach
han ky » hanh ky, than ky, nhan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( hoc trinh ngan ((ky huyet) or (ly thuyet)) hoc hoc ) or ( su sach han ky thuat co hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc trinh ngan ((ky huyet) OR (ly thuyet)) hoc hoc ) OR ( su sach han ky thuat co hoc )).
• Adding a wildcard symbol may retrieve word variants: (( hoc trinh ngan ((ky huyet) or (ly thuyet)) hoc hoc ) or ( su sach han ky thuat co hoc ))*.