Perhaps you should try some spelling variations:
trien khai » trien nha
thuoc sach » hoc sach, nuoc sach, thuat sach
tren khoi » trien khoa, trinh khoi, tien khi
sach xin » sach kinh, sach tien, sach xa
chi khoa » nhi khoa, chua khoa, thai khoa
khoa hoc » hoa hoc
xin chi » tin chi, dinh chi, linh chi
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thuoc sach xin chi khoa hoc ) or ( tu sach ((tren khoi) OR (trien khai)) khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuoc sach xin chi khoa hoc ) OR ( tu sach ((tren khoi) OR (trien khai)) khoa hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuoc sach xin chi khoa hoc ) or ( tu sach ((tren khoi) OR (trien khai)) khoa hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( thuoc sach xin chi khoa hoc ) or ( tu sach ((tren khoi) OR (trien khai)) khoa hoc ))*.