schwa sound in IPA?

Solution 1:

The schwa is written as ə in the International Phonetic Alphabet. Some linguists, however, assert that there is no schwa before the l sound in English words like fossil, possible, etc. Others are of the opposite opinion, whence the discrepancy you observed.

Solution 2:

The superscript schwa in the transcriptions given in good dictionaries indicates that a schwa is possible in such words. It doesn't indicate that it will always be there when spoken by a native speaker. It does not represent a small schwa either, it's a possible schwa.

Whenever there is the possibility of a syllabic consonant in English (usually /l,n,m, r/) there is always also the possibility of a preceding schwa in English.