for typecode, ref in query_ref.iter():
if(ref=='$'):
classes = buff[0:buff.index('#')]
bookclass = ""
noticekoha = buff[buff.index('#')+1]
title = buff[buff.index('#')+2]
# Clean book's class by comparing the 930/a subfields with 995/k subfields ( both 930/a and 995/k can be replicated)
# because sometimes these fields are correspond to different value, even though it should always be the same
# if they are different, finding the more suitable one to be used as the book's class
# for example, sometimes 930/a = D8 ENG/S, while 995/k = D 8.02 SIPP for the same book
# from the above example, the 995/k subfield is preferred because it is in the right format (having '.')
for cls in classes:
try:
cls = Classification.classtrim(cls)
if(cls == ValueError): continue
try:
k = cls.index('.')
if(k>2): continue
try:
k = cls.index('-')
for j in cls:
if(j=='-'):
j = ' '
bookclass = cls
break
except ValueError as ve:
bookclass = cls
break
except ValueError as ve:
