Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien cua » truyen cua, trien nha, tri cua
sach tieu » sach thieu, sach tien, cach tieu
chuan hoa » chuan doan, khuan khoa, chuyen hoa
cua khoa » chua khoa, sua khoa, qua khoa
khoa hoc » hoa hoc
chuan ha » chuan he, quan ha, chuan bi
vu sach » vu bach, su sach, vu khach

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 trien cua khoa hoc ) or ( vu sach tieu ((chuan hoa) OR (chuan ha)) hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach trien cua khoa hoc ) OR ( vu sach tieu ((chuan hoa) OR (chuan ha)) hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu sach trien cua khoa hoc ) or ( vu sach tieu ((chuan hoa) OR (chuan ha)) hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( vu sach trien cua khoa hoc ) or ( vu sach tieu ((chuan hoa) OR (chuan ha)) hoc ))*.