How do I know which declension pattern a noun belongs to in the Langenscheidt pocket dictionary?

Question

I have this somewhat-useful little yellow book sitting in my backpack, and I've noticed that it has a table in the back that gives 16 groups of noun declension patterns. For whatever reason, these have been fairly easy for me to remember, and I'd like to make broader use of them. Except, I can't figure out how to know which group a noun belongs to.

• There doesn't seem to be a numeric indicator in the individual entries
• The genitive + plural is ambiguous (I was not correct about this)
• Matching exact endings doesn't make sense because some words have endings that don't fit the groups (Buch is a simple example)
• General ending matching would make some sense, but I don't know how to go about it. (i.e. would Buch be a group 1 word because it ends in a consonant?)

It's quite possible that this is something simple that I haven't learned. I'm a self-taught German student. I am familiar with the basic concept of declension (thanks to a minor in Russian), and have worked through a couple of German 1 books, but they don't seem to provide anything specifically helpful. Obviously, these references give their own rules-of-thumb about declension patterns, but it all feels very open ended.

Does anyone use the Langenscheidt dictionary this way who could help? Or do people just know the underlying rules of the patterns and only look at the table for a quick brush-up?

edit Spoiler: The answer is that the second bullet is actually the correct way to view it. When looking at groups 6 & 8, they seem to look the same: the table is the same, and the plural ends in "en". However, group 8 adds the "en" to the plural, where 6 does not. This is actually quite evident in the listings, because 6 is listed as (-s; -) and 8 is listed as (-s; -en)

edit: Here is the primary form of the table. Most of the numbered patterns also have listed sub patterns (e.g. 9 lists 1 - a and o(n) > en: Drama, Dramen) 2 -on and um> a: Lexicon, Lexica). I'm not listing them all here, partly for time, partly because I'm not entirely sure about reproducing the table in its entirety.

-  nom    gen   dat   acc         nom        gen    dat   acc

1) Bild   ~(e)s ~(e)  ~        5) Strahl     ~(e)s, ~(e)  ~
   Bilder ~     ~n    ~           Strahlen   ~      ~     ~

2) Reis   ~es   ~(e)  ~        6) Lappen     ~s     ~     ~
   Reiser ~     ~n    ~           Lappen     ~      ~     ~

3) Arm    ~(e)s ~(e)  ~        7) Maler      ~s     ~     ~
   Arme   ~     ~n    ~           Maler      ~      ~n    ~

4) Greis  ~es   ~(e)  ~        8) Untertan   ~s     ~     ~
   Greise ~     ~n    ~           Untertanen ~      ~     ~

--------------------------------------------------------------------

9)  Studium ~s   ~    ~       13) Knabe      ~n     ~n    ~n
    Studien ~    ~    ~           Knaben     ~      ~     ~

10) Auge    ~s   ~    ~       14) Truebsal   ~      ~     ~
    Augen   ~    ~    ~           Truebsale  ~      ~n    ~

11) Genie   ~s   ~    ~       15) Blume      ~      ~     ~
    Genies  ~    ~    ~           Blumen     ~      ~     ~

12) Baer    ~en  ~en  ~en     16) Frau       ~      ~     ~
    Baeren  ~    ~    ~           Frauen     ~      ~     ~

Answer 1

The pocket dictionary in question gives the genitive and plural forms of nouns (in parentheses and in italics), which is sufficient to determine the other forms with the help of the table. It should be noted that for those nouns which have an optional e in some forms, this is indicated in the genitive form.

However, an older version of the dictionary actually lists the number of the declension scheme instead, for example for Buch it lists “(1²)”.

As an aside, looking at several Langenscheidt pocket dictionaries I notice that the older ones are designed to be used by speakers of both of the involved languages and hence include grammar information for both languages, while newer ones are targeted at speakers of one of the two languages.