'Lookup all rows referenced by values.
@param key: the key Field
@param values: the values
@param fields: the fields to retrieve'

def lookup_rows(self, key, values, fields=[]):

    s3db = current.s3db
    table = self.table
    utable = s3db.cr_shelter_unit
    left = utable.on((utable.id == table.shelter_unit_id))
    count = len(values)
    if (count == 1):
        query = (table.id == values[0])
    else:
        query = table.id.belongs(values)
    limitby = (0, count)
    rows = current.db(query).select(table.id, table.date, utable.name, left=left, limitby=limitby)
    return rows
