Perhaps you should try some spelling variations:
sach danh » sach tranh, sach dao, sach dung
thu lanh » thu canh, thi lanh, thu anh
su sach » so sach, vu sach
danh ky » hanh ky, dan ky, dang ky
do hoc » co hoc, do hoa, du hoc
dao ky » cao ky, dan ky, do ky
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach danh ky thuat do hoc ) or ( thu lanh dao ky thuat o hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach danh ky thuat do hoc ) OR ( thu lanh dao ky thuat o hoc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach danh ky thuat do hoc ) or ( thu lanh dao ky thuat o hoc ))*.