Perhaps you should try some spelling variations:
trien qua » trien quy, trien quang, thien quan
trien cua » truyen cua, trien nha, tri cua
cach tieu » sach thieu, cach bien, cach tu
vu khach » vu khanh, vu khac, vay khach
khoa hoc » hoa hoc
chuan ha » chuan he, quan ha, chuan bi
vu cach » va cach, ve cach, vu bach
ha hoc » hoa hoc, nha hoc, va hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu khach ((trien qua) or (trien cua)) khoa hoc ) or ( vu cach tieu chuan ha hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu khach ((trien qua) OR (trien cua)) khoa hoc ) OR ( vu cach tieu chuan ha hoc )).
• Adding a wildcard symbol may retrieve word variants: (( vu khach ((trien qua) or (trien cua)) khoa hoc ) or ( vu cach tieu chuan ha hoc ))*.